Introduce coding standards workflow

workflow-templates/coding-standards.yml

@@ -0,0 +1,38 @@
+
+name: "Coding Standards"
+
+on: ["pull_request", "push"]
+
+jobs:
+  coding-standards:
+    name: "Coding Standards"
+    runs-on: "ubuntu-latest"
+
+    strategy:
+      matrix:
+        php-version:
+          - "7.4"
+
+    steps:
+      - name: "Checkout"
+        uses: "actions/checkout@v2"
+
+      - name: "Install PHP"
+        uses: "shivammathur/setup-php@v2"
+        with:
+          coverage: "none"
+          php-version: "${{ matrix.php-version }}"
+          tools: "cs2pr"
+
+      - name: "Cache dependencies installed with composer"
+        uses: "actions/cache@v2"
+        with:
+          path: "~/.composer/cache"
+          key: "php-${{ matrix.php-version }}-composer-locked-${{ hashFiles('composer.lock') }}"
+          restore-keys: "php-${{ matrix.php-version }}-composer-locked-"
+
+      - name: "Install dependencies with composer"
+        run: "composer install --no-interaction --no-progress --no-suggest"
+
+      - name: "Run PHP Code Beautifier"
+        run: "vendor/bin/phpcs -q --no-colors --report=checkstyle | cs2pr"