Add CI workflow to build the MakeCode project (V2 only).

.github/workflows/build-project.yml

@@ -0,0 +1,27 @@
+name: Build MakeCode Project
+
+on:
+  push:
+    branches: '*'
+  pull_request:
+    branches: '*'
+
+jobs:
+  build-project:
+    name: Build MakeCode Project
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - name: Setup Node.js
+      uses: actions/setup-node@v4
+      with:
+        node-version: '20'
+    - name: Install dependencies
+      run: |
+        npm install -g pxt
+        pxt target microbit --no-save
+        pxt install
+    - name: Build locally with Docker
+      run: PXT_COMPILE_SWITCHES=csv---mbcodal pxt build --localbuild
+      env:
+        CI: true