ci: add initial GH workflow

.github/workflows/check.yaml

@@ -0,0 +1,19 @@
+name: Static analysis
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  yaml:
+    if: |
+      github.event_name == 'push' ||
+      github.event_name == 'pull_request' &&
+      github.event.pull_request.head.repo.full_name != github.repository
+
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/checkout@v3
+      - run: pip3 install pykwalify yamllint
+      - run: pykwalify --data-file games.yaml --schema-file schema.yaml
+      - run: yamllint games.yaml

.yamllint.yaml

@@ -0,0 +1,4 @@
+extends: default
+
+rules:
+  line-length: disable