Include mimimal example

Author: Ghostbird

README.md

@@ -1,3 +1,28 @@
 # Docker image .NET MAUI Android
 
 Builds a [docker image](https://hub.docker.com/r/conneqthub/dotnet-maui-android) that allows containerised builds of .NET 9.0 MAUI Android 35 apps.
+
+The goal of the resulting image is that you can run `dotnet build` on a MAUI Android workspace without first needing to install additional software.
+
+## Basic approach
+
+- Start the docker image
+- Get the source code you want to build
+- `dotnet build`
+
+## Minimal example of steps in Github Actions
+
+```yaml
+steps:
+  - name: Checkout
+    uses: actions/checkout@v4
+  - name: Build
+    shell: bash
+    run: dotnet build
+  - name: Upload AAB
+    uses: actions/upload-artifact@v4
+    with:
+      name: aab
+      path: bin/Release/net9.0-android/com.example.app-Signed.aab
+      if-no-files-found: error
+      retention-days: 1