Add super-lint to enable OpenAPI linting

.github/workflows/lint.yml

@@ -0,0 +1,34 @@
+name: Lint
+
+on: # yamllint disable-line rule:truthy
+  pull_request: {}
+  push:
+    branches: [main]
+    paths-ignore:
+      - 'README.md'
+
+jobs:
+  build:
+    name: Lint
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+      packages: read
+      # To report GitHub Actions status checks
+      statuses: write
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          # super-linter needs the full git history to get the
+          # list of files that changed across commits
+          fetch-depth: 0
+
+      - name: Super-linter
+        uses: super-linter/[email protected]
+        env:
+          DEFAULT_BRANCH: main
+          VALIDATE_OPENAPI: true
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

openapi.yaml

@@ -1,6 +1,4 @@
 openapi: 3.1.0
-
-# Metadata about the API
 info:
   title: Train Travel API
   description: API for finding and booking train trips across Europe.