only build docs on release

Author: wdm0006

.github/workflows/docs.yml

@@ -1,7 +1,7 @@
 name: "Master Docs Publication"
 on:
-  push:
-    branches: [ master ]
+  release:
+    types: created
 
 jobs:
   docs:
@@ -22,4 +22,4 @@ jobs:
         uses: peaceiris/actions-gh-pages@v3
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
-          publish_dir: ./docs/build/html
+          publish_dir: ./docs/build/html