Make workflow push back changes

.github/workflows/update.yml

@@ -1,3 +1,5 @@
+name: Manifest updater
+
 on:
   push:
     branches: [ main ]
@@ -7,6 +9,8 @@ on:
 jobs:
   build:
     runs-on: ubuntu-latest
+    permissions:
+      contents: write 
     steps:
     - uses: actions/checkout@v4
     - uses: actions/setup-node@v4
@@ -14,3 +18,9 @@ jobs:
         node-version: '20'
         cache: 'npm'
     - run: node update.js
+    - run: |
+        git config user.name "github-actions[bot]"
+        git config user.email "github-actions[bot]@users.noreply.github.com"
+        git add manifest.json
+        git commit -m "Generate manifest.json" || exit 0
+        git push