Add markdown checker

.github/workflows/integrate.yaml

@@ -0,0 +1,16 @@
+name: lint
+
+on:
+  pull_request:
+    branches: [ 'main' ]
+
+jobs:
+  lint:
+    runs-on: 'ubuntu-latest'
+    steps:
+      - name: 'Check out repository'
+        uses: actions/checkout@v4
+      - name: 'Install markdownlint-cli'
+        run: npm install -g markdownlint-cli
+      - name: 'Lint markdown files'
+        run: markdownlint '**/*.md'