Add performance test action

.github/workflows/performance-check.yml

@@ -0,0 +1,20 @@
+on:
+  pull_request:
+  push:
+    branches:
+    - main
+    - 'releases/*'
+jobs:
+  performance-test:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v3
+
+    - name: Run performance tests
+      uses: swissspidy/wp-performance-action@main
+      with:
+        plugins: |
+          ./
+        urls: |
+          /