feat: multi input file support (Azure#214)

# Pull Request

## Description

Support for multiple input files that get merged together.

Docs updates for new version of complete-multi-region Terraform module.

Associated PR for starter module:
Azure/alz-terraform-accelerator#175

## License

By submitting this pull request, I confirm that my contribution is made
under the terms of the projects associated license.

Author: jaredfholgate

Diff for: CONTRIBUTING.md

@@ -101,6 +101,13 @@ Copy-Item -Path "$exampleFolder/inputs-azure-devops-terraform-complete-multi-reg
 Copy-Item -Path "$exampleFolder/inputs-github-terraform-complete-multi-region.yaml" -Destination "$terraformConfigFolder/inputs-github.yaml" -Force
 Copy-Item -Path "$exampleFolder/inputs-local-terraform-complete-multi-region.yaml" -Destination "$terraformConfigFolder/inputs-local.yaml" -Force
 
+$exampleFolder = "$targetFolder/code/ALZ-PowerShell-Module/docs/wiki/examples/starter-module-config/complete-multi-region"
+
+Copy-Item -Path "$exampleFolder/config-hub-and-spoke-vnet-multi-region.yaml" -Destination "$terraformConfigFolder/config-hub-and-spoke-vnet-multi-region.yaml" -Force
+Copy-Item -Path "$exampleFolder/config-hub-and-spoke-vnet-single-region.yaml" -Destination "$terraformConfigFolder/config-hub-and-spoke-vnet-single-region.yaml" -Force
+Copy-Item -Path "$exampleFolder/config-virtual-wan-multi-region.yaml" -Destination "$terraformConfigFolder/config-virtual-wan-multi-region.yaml" -Force
+Copy-Item -Path "$exampleFolder/config-virtual-wan-single-region.yaml" -Destination "$terraformConfigFolder/config-virtual-wan-single-region.yaml" -Force
+
 ```
 
 >IMPORTANT! - Now you'll need to update the input files with your settings for VCS, etc.
@@ -197,12 +204,14 @@ Deploy-Accelerator `
     -bootstrapModuleOverrideFolderPath "/$targetFolder/code/accelerator-bootstrap-modules" `
     -starterModuleOverrideFolderPath "/$targetFolder/code/alz-terraform-accelerator/templates" `
     -output "/$targetFolder/acc/terraform/output/azuredevops" `
-    -inputs "/$targetFolder/acc/terraform/config/inputs-azuredevops.yaml" `
+    -inputs "/$targetFolder/acc/terraform/config/inputs-azuredevops.yaml", "/$targetFolder/acc/terraform/config/config-hub-and-spoke-vnet-multi-region.yaml" `
     -verbose `
     -replaceFiles  # This will replace the files in the output folder with the files in the bootstrap and starter modules, so any updates are taken into account
 
 ```
 
+>NOTE: The `config-hub-and-spoke-vnet-multi-region.yaml` file is an example. You can use any of the other configuration files.
+
 ### Terraform GitHub
 
 Run this from the VSCode terminal for the ALZ-PowerShell-Module repository:
@@ -221,12 +230,14 @@ Deploy-Accelerator `
     -bootstrapModuleOverrideFolderPath "/$targetFolder/code/accelerator-bootstrap-modules" `
     -starterModuleOverrideFolderPath "/$targetFolder/code/alz-terraform-accelerator/templates" `
     -output "/$targetFolder/acc/terraform/output/github" `
-    -inputs "/$targetFolder/acc/terraform/config/inputs-github.yaml" `
+    -inputs "/$targetFolder/acc/terraform/config/inputs-github.yaml", "/$targetFolder/acc/terraform/config/config-hub-and-spoke-vnet-multi-region.yaml" `
     -verbose `
     -replaceFiles  # This will replace the files in the output folder with the files in the bootstrap and starter modules, so any updates are taken into account
 
 ```
 
+>NOTE: The `config-hub-and-spoke-vnet-multi-region.yaml` file is an example. You can use any of the other configuration files.
+
 ### Terraform Local
 
 Run this from the VSCode terminal for the ALZ-PowerShell-Module repository:
@@ -245,8 +256,10 @@ Deploy-Accelerator `
     -bootstrapModuleOverrideFolderPath "/$targetFolder/code/accelerator-bootstrap-modules" `
     -starterModuleOverrideFolderPath "/$targetFolder/code/alz-terraform-accelerator/templates" `
     -output "/$targetFolder/acc/terraform/output/local" `
-    -inputs "/$targetFolder/acc/terraform/config/inputs-local.yaml" `
+    -inputs "/$targetFolder/acc/terraform/config/inputs-local.yaml", "/$targetFolder/acc/terraform/config/config-hub-and-spoke-vnet-multi-region.yaml" `
     -verbose `
     -replaceFiles  # This will replace the files in the output folder with the files in the bootstrap and starter modules, so any updates are taken into account
 
 ```
+
+>NOTE: The `config-hub-and-spoke-vnet-multi-region.yaml` file is an example. You can use any of the other configuration files.

Diff for: docs/wiki/[User-Guide]-Quick-Start-Phase-2-Azure-DevOps.md

@@ -152,14 +152,16 @@ Although you can just run `Deploy-Accelerator` and fill out the prompted inputs,
     - [Terraform Complete Starter Module][wiki_starter_module_terraform_complete]: Management groups, policies, hub networking with fully custom configuration.
 1. In your PowerShell Core (pwsh) terminal run the module:
 
+    >NOTE: The following examples include 2 input files. This is the recommended approach for the `complete_multi_region` starter module. However, all inputs can be combined into a single file if desired and other starter modules only require a single input file.
+
     ```pwsh
     # Windows (adjust the paths to match your setup)
-    Deploy-Accelerator -inputs "c:\accelerator\config\inputs.yaml" -output "c:\accelerator\output"
+    Deploy-Accelerator -inputs "c:\accelerator\config\inputs.yaml", "c:\accelerator\config\networking.yaml" -output "c:\accelerator\output"
     ```
 
     ```pwsh
     # Linux/Mac (adjust the paths to match your setup)
-    Deploy-Accelerator -inputs "/accelerator/config/inputs.yaml" -output "/accelerator/output"
+    Deploy-Accelerator -inputs "/accelerator/config/inputs.yaml", "/accelerator/config/networking.yaml" -output "/accelerator/output"
     ```
 
 1. You will see a Terraform `init` and `apply` happen.

Diff for: docs/wiki/[User-Guide]-Quick-Start-Phase-2-GitHub.md

@@ -139,12 +139,16 @@ Although you can just run `Deploy-Accelerator` and fill out the prompted inputs,
     - [Terraform Complete Starter Module][wiki_starter_module_terraform_complete]: Management groups, policies, hub networking with fully custom configuration.
 1. In your PowerShell Core (pwsh) terminal run the module:
 
+    >NOTE: The following examples include 2 input files. This is the recommended approach for the `complete_multi_region` starter module. However, all inputs can be combined into a single file if desired and other starter modules only require a single input file.
+
     ```pwsh
     # Windows (adjust the paths to match your setup)
-    Deploy-Accelerator -inputs "c:\accelerator\config\inputs.yaml" -output "c:\accelerator\output"
+    Deploy-Accelerator -inputs "c:\accelerator\config\inputs.yaml", "c:\accelerator\config\networking.yaml" -output "c:\accelerator\output"
+    ```
 
+    ```pwsh
     # Linux/Mac (adjust the paths to match your setup)
-    Deploy-Accelerator -inputs "/accelerator/config/inputs.yaml" -output "/accelerator/output"
+    Deploy-Accelerator -inputs "/accelerator/config/inputs.yaml", "/accelerator/config/networking.yaml" -output "/accelerator/output"
     ```
 
 1. You will see a Terraform `init` and `apply` happen.

Diff for: docs/wiki/[User-Guide]-Quick-Start-Phase-2-Local.md

@@ -128,14 +128,16 @@ Although you can just run `Deploy-Accelerator` and fill out the prompted inputs,
     - [Terraform Complete Starter Module][wiki_starter_module_terraform_complete]: Management groups, policies, hub networking with fully custom configuration.
 1. In your PowerShell Core (pwsh) terminal run the module:
 
+    >NOTE: The following examples include 2 input files. This is the recommended approach for the `complete_multi_region` starter module. However, all inputs can be combined into a single file if desired and other starter modules only require a single input file.
+
     ```pwsh
     # Windows (adjust the paths to match your setup)
-    Deploy-Accelerator -inputs "c:\accelerator\config\inputs.yaml" -output "c:\accelerator\output"
+    Deploy-Accelerator -inputs "c:\accelerator\config\inputs.yaml", "c:\accelerator\config\networking.yaml" -output "c:\accelerator\output"
     ```
 
     ```pwsh
     # Linux/Mac (adjust the paths to match your setup)
-    Deploy-Accelerator -inputs "/accelerator/config/inputs.yaml" -output "/accelerator/output"
+    Deploy-Accelerator -inputs "/accelerator/config/inputs.yaml", "/accelerator/config/networking.yaml" -output "/accelerator/output"
     ```
 
 1. You will see a Terraform `init` and `apply` happen.

Diff for: docs/wiki/[User-Guide]-Quick-Start-Phase-3.md

@@ -37,6 +37,10 @@ Follow the steps below to deploy the landing zone locally. If you want to hook i
 
 #### 3.1.3.1 Bicep
 
+The Bicep option outputs a `deploy-local.ps1` file that you can use to deploy the ALZ.
+
+>NOTE: If you set the `grant_permissions_to_current_user` input to `false` in the bootstrap, you will need to set permissions on your management group and subscriptions before the commands will succeed.
+
 1. Ensure you have the latest versions of the [AZ PowerShell Module](https://learn.microsoft.com/en-us/powershell/azure/install-azure-powershell) and [Bicep](https://learn.microsoft.com/en-us/azure/azure-resource-manager/bicep/install) installed.
 1. Open a new PowerShell Core (pwsh) terminal or use the one you already have open.
 1. Navigate to the directory shown in the `module_output_directory_path` output from the bootstrap.
@@ -49,13 +53,16 @@ Follow the steps below to deploy the landing zone locally. If you want to hook i
 
 #### 3.1.3.2 Terraform
 
+The Terraform option outputs a `deploy-local.ps1` file that you can use to deploy the ALZ.
+
+>NOTE: If you set the `grant_permissions_to_current_user` input to `false` in the bootstrap, you will need to set permissions on your management group, subscriptions and storage account before the commands will succeed.
+
 1. Open a new PowerShell Core (pwsh) terminal or use the one you already have open.
 1. Navigate to the directory shown in the `module_output_directory_path` output from the bootstrap.
-1. If you choose to deploy the bootstrap resources in Azure, then you will need to navigate to the Azure Portal and find you storage account.
-1. Make note of the `Resource Group Name`, `Storage account name`and `Container Name` from the storage account.
-1. If you did not choose to deploy the bootstrap resources in Azure, type `terraform init` and hit enter.
-1. If you choose to deploy the bootstrap resources in Azure, type `terraform init -backend-config="resource_group_name=<Resource Group Name>" -backend-config="storage_account_name=<Storage account name>" -backend-config="container_name=<Container Name>" -backend-config="key=terraform.tfstate" -backend-config="use_azuread_auth=true"` , replacing the items in angle brackets and hit enter.
-1. Type `terraform plan -out=tfplan` and hit enter.
-1. Review the plan. Use `terraform show tfplan` to see the plan details.
-1. If you are happy with the plan, then type `terraform apply tfplan` and hit enter.
+1. (Optional) Ensure you are still logged in to Azure using `az login --tenant 00000000-0000-0000-0000-000000000000`.
+1. (Optional) Connect to your target subscription using `az account set --subscription 00000000-0000-0000-0000-000000000000`.
+1. (Optional) Examine the `./scripts/deploy-local.ps1` to understand what it is doing.
+1. Run `./scripts/deploy-local.ps1`.
+1. A plan will run and then you'll be prompted to check it and run the deploy.
+1. Type `yes` and hit enter to run the deploy.
 1. The ALZ will now be deployed, this may take some time.