add github action

.github/workflows/scenario-schema.yml

@@ -0,0 +1,28 @@
+name: Validate scenarios against schema
+on:
+  push:
+    paths:
+      - 'data/scenarios/**.yaml'
+    branches:
+      - main
+  pull_request:
+    paths:
+      - 'data/scenarios/**.yaml'
+    branches:
+      - main
+jobs:
+  validate-scenario-schema:
+    name: Validate scenarios schema
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: "3.10"
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install check-jsonschema
+      - run: |
+          find data/scenarios -name "*.yaml" -type f -print0 | xargs -0 check-jsonschema --base-uri $(git rev-parse --show-toplevel)/data/schema/scenario.json --schemafile data/schema/scenario.json