Update GitHub Actions for format check in the frontend; Separate linting with formating

Author: leekahung

.github/workflows/pr-check.yml

@@ -70,4 +70,7 @@ jobs:
         run: npm run build
 
       - name: Run linting checks
-        run: npm run lint
+        run: npm run lint
+
+      - name: Run format checks
+        run: npx prettier --check .