Convert GitHub Actions workflow to new format

Author: ScottBrenner

.github/main.workflow

@@ -0,0 +1,18 @@
+name: Lint
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  lint:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: ansible/ansible-lint-action@master
+      name: Lint
+      with:
+        ACTION_PLAYBOOK_NAME: "wordpress-nginx/site.yml"