add workflow

.github/workflows/build.yml

@@ -0,0 +1,31 @@
+name: Build
+
+on: [ push, pull_request ]
+
+jobs:
+  tests:
+    runs-on: "ubuntu-latest"
+    strategy:
+      matrix:
+        php-version:
+          - "8.2"
+          - "8.3"
+    steps:
+      - name: "Checkout"
+        uses: "actions/checkout@v2"
+
+      - name: "Install PHP"
+        uses: "shivammathur/setup-php@v2"
+        with:
+          php-version: "${{ matrix.php-version }}"
+          tools: "cs2pr"
+
+      - name: "Install dependencies with Composer"
+        uses: "ramsey/composer-install@v2"
+
+      - name: "Run phpcs"
+        if: ${{ matrix.php-version == '8.3' }}
+        run: "vendor/bin/phpcs -n -s --report=checkstyle | cs2pr"
+
+      - name: "Run PHPUnit"
+        run: "vendor/bin/phpunit"