Add devcontanier

Author: razzeee

.devcontainer/Dockerfile

@@ -0,0 +1,6 @@
+FROM fedora:30
+
+RUN dnf install -y \
+        ruby rubygems rubygem-bundler rubygem-json \
+        git gcc gcc-c++ make redhat-rpm-config patch \
+        ruby-devel libffi-devel zlib-devel

.devcontainer/devcontainer.json

@@ -0,0 +1,20 @@
+// For format details, see https://aka.ms/devcontainer.json. For config options, see the README at:
+// https://github.com/microsoft/vscode-dev-containers/tree/v0.205.2/containers/ruby
+{
+	"name": "Ruby",
+	"build": {
+		"dockerfile": "Dockerfile",
+	},
+	// Set *default* container specific settings.json values on container create.
+	"settings": {},
+	// Add the IDs of extensions you want installed when the container is created.
+	"extensions": [
+		"rebornix.Ruby"
+	],
+	// Use 'forwardPorts' to make a list of ports inside the container available locally.
+	// "forwardPorts": [],
+	// Use 'postCreateCommand' to run commands after the container is created.
+	"postCreateCommand": "gem install bundler:2.3.5 && bundle install",
+	// Comment out connect as root instead. More info: https://aka.ms/vscode-remote/containers/non-root.
+	// "remoteUser": "vscode"
+}

README.md

@@ -15,11 +15,17 @@ Add the middleman binary location (probably ~/bin) to $PATH.
 
 To run a local web server to test the site:
 
+```sh
     bundle exec middleman server
+```
 
 Edit the haml/scss files and commit your changes, pushing to
 origin/source.
 
+## Devcontainer
+
+You can also use the devcontainer, for e.g. with VSCode. It should setup automatically and just expects you to run the testing command from above or command you would like to run.
+
 ## Deployment
 
 Pushing new commits automatically causes to trigger new build