ci: add repository health check

Author: codegraphtheory

.github/workflows/ci.yml

@@ -0,0 +1,14 @@
+name: CI
+
+on:
+  pull_request:
+  push:
+    branches: [main]
+
+jobs:
+  repository-health:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Check repository has public surface
+        run: test -f README.md || test -f index.html