Format branches list in docs.yml

We just need to use main branch now. ABM3_develop has been renamed to main.

Author: bhargavasana

.github/workflows/docs.yml

@@ -1,7 +1,8 @@
 name: Publish documents
 on:
   push:
-    branches: [main, ABM3_develop]
+    branches:
+      - main
 jobs:
   build:
     name: Deploy docs to GitHub Pages
@@ -19,4 +20,4 @@ jobs:
         uses: peaceiris/actions-gh-pages@v3
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
-          publish_dir: ./site
+          publish_dir: ./site