Add YAML linter

Author: arnested

.github/workflows/yaml.yml

@@ -0,0 +1,22 @@
+---
+on: pull_request
+name: YAML
+permissions:
+  contents: read
+
+# Detect if this action is already running, and cancel it.
+# This most likely happened because a second push has been made to a branch.
+concurrency:
+  group: ${{ github.repository_id }}-${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  yaml-cs-fixer:
+    name: Yamllint
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@v5
+      - name: Run Yamllint
+        uses: frenck/action-yamllint@v1.5.0
+        with:
+          strict: true