Squash merge branch linting

.github/workflows/lint-code.yml

@@ -0,0 +1,49 @@
+name: Code Linting
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  lint:
+    name: Lint all code
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Validate composer.json and composer.lock
+        run: composer validate --strict
+
+      - name: Cache Composer packages
+        id: composer-cache
+        uses: actions/cache@v2
+        with:
+          path: vendor
+          key: ${{ runner.os }}-php-${{ hashFiles('**/composer.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-php-
+
+      - name: Install dependencies
+        run: composer install --prefer-dist --no-progress --ignore-platform-reqs
+
+      - name: Validate workflow files (YAML)
+        run: npm run validate:yaml
+
+      - name: Lint Plugin code (PHP)
+        run: composer run lint:php
+
+      - name: Lint Plugin scripts (JS)
+        run: composer run format:js:fix && composer run lint:js
+
+      #- name: Lint stylesheets (CSS)
+      #  run: composer run lint:css
+        
+      #- name: Lint templates (HTML)
+      #  run: composer run lint:html
+
+      - name: Lint documentation (Markdown)
+        run: composer run lint:md