windows-dotnet-functionapp-on-azure.yml refactor and .NET update

[VGsss]

Added the "What this script will do" section to make it more beginner friendly
Added the "BEWARE" section for first timers and unaware users
Refactored the section "CONFIGURATION"
Updated the DOTNET_VERSION value to '6.0.x' so it can work with Azure Functions 4.x (https://docs.microsoft.com/en-us/azure/azure-functions/functions-versions)
Updated the step "setup-dotnet" to v2

[ghost]

Thank you for your submission, we really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.

❌ VGsss sign now
_{You have signed the CLA already but the status is still pending? Let us recheck it.}