Add YAML workflow at GitHub Actions

Author: tmknom

.github/workflows/yaml.yml

@@ -0,0 +1,24 @@
+name: YAML
+on:
+  pull_request:
+
+jobs:
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - name: Checkout
+        uses: actions/[email protected]
+      - name: yamllint
+        run: docker run --rm -v ${PWD}:/work tmknom/yamllint --strict .
+
+  format:
+    name: Format
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - name: Checkout
+        uses: actions/[email protected]
+      - name: Prettier
+        run: docker run --rm -v ${PWD}:/work tmknom/prettier --list-different --parser=yaml '**/*.y*ml'