Add GitHub Action for PHP CodeSniffer.

Author: Potherca

.github/workflows/quality-checks.yml

@@ -13,3 +13,11 @@ jobs:
       - uses: "docker://composer"
         with:
           args: composer validate --strict --working-dir=solid/
+
+  php-codesniffer:
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/checkout@v2
+      - uses: pipeline-components/php-codesniffer@master
+        with:
+          options: --standard=build/phpcs.xml.dist