Add simple performance tests

.github/workflows/performance-tests.yml

@@ -0,0 +1,35 @@
+name: Performance Tests
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+jobs:
+  performance-tests:
+    timeout-minutes: 60
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v4
+
+    - name: Setup Node
+      uses: actions/setup-node@v3
+      with:
+        node-version-file: '.nvmrc'
+        cache: npm
+
+    - name: Install dependencies
+      run: npm ci
+
+    - name: Build plugin
+      run: npm run build
+
+    - name: Run performance tests
+      uses: swissspidy/wp-performance-action@main
+      with:
+        plugins: |
+          ./
+        urls: |
+          /
+          /sample-page/