chore: rename built script file

Author: Candinya

.github/workflows/dev-page.yml

@@ -51,6 +51,8 @@ jobs:
     runs-on: ubuntu-latest
     name: Deploy
     steps:
+      - name: Rename script ext # to prevent MIME type conflict (don't know why it's `application/node`)
+        run: mv widget.umd.cjs widget.umd.js
       - name: Deploy to GitHub Pages
         id: deployment
         uses: actions/deploy-pages@v4