only deploy on main

Author: billnapier

.github/workflows/publish_docs.yml

@@ -23,6 +23,7 @@ jobs:
       with:
         path: 'generated-pages'
   deploy:
+    if: github.ref == 'refs/heads/main'
     environment:
       name: 'github-pages'
       url: '${{ steps.deployment.outputs.page_url }}'