docs: update for v3

README.md

@@ -627,10 +627,10 @@ on:
       - master
 
 jobs:
-  build-deploy:
+  deploy:
     runs-on: ubuntu-18.04
     steps:
-    - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
 
       - name: Setup Node
         uses: actions/setup-node@v1
@@ -652,11 +652,10 @@ jobs:
       - run: npm run generate
 
       - name: deploy
-      uses: peaceiris/actions-gh-pages@v2
-      env:
-        ACTIONS_DEPLOY_KEY: ${{ secrets.ACTIONS_DEPLOY_KEY }}
-        PUBLISH_BRANCH: gh-pages
-        PUBLISH_DIR: ./dist
+        uses: peaceiris/actions-gh-pages@v3
+        with:
+          deploy_key: ${{ secrets.ACTIONS_DEPLOY_KEY }}
+          publish_dir: ./dist
 ```
 
 ### ⭐️ Static Site Generators with Python