ci: Add GitHub Actions workflow for building and testing extension

Author: scott-the-programmer

.github/workflows/ci.yml

@@ -0,0 +1,43 @@
+name: CI
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [16.x, 18.x]
+
+    steps:
+    - uses: actions/checkout@v3
+    
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v3
+      with:
+        node-version: ${{ matrix.node-version }}
+        cache: 'npm'
+    
+    - name: Install dependencies
+      run: npm ci
+    
+    - name: Build
+      run: npm run build
+    
+    - name: Test
+      run: npm test
+    
+    - name: Upload build artifacts
+      uses: actions/upload-artifact@v3
+      with:
+        name: extension-build
+        path: |
+          dist/
+          manifest.json
+          popup.html
+          icons/