PHP app.yaml，GAE的新手，不知道如何设置

I have a single page website built on bootstrap 3, that I am trying to move to Google Apps Engine. I Scaffold my sites using php, and all the content is showing but not the styles and javascript. My site is basically set up as follows

• _/js/bootstrap.js
• _/js/custom.js
• _/fonts/glypicon ...etc
• _/css/bootstrap.css
• _/css/custom.css
• _/php/ .. all my php files go here ...
• index.php

can someone help me setup my app.yaml for this? I am new to GAE, and am a little confused by this.

From: https://developers.google.com/appengine/docs/php/config/appconfig

application: myapp     # of course, replace with your app name
version: 1
runtime: php
api_version: 1

handlers:

# Serve php scripts.
- url: /(.+\.php)$
  script: \1

- url: /
  script: index.php

- url: /index\.html
  script: index.php

- url: /_/css
  static_dir: _/css

- url: /_/js
  static_dir: _/js

- url: /_/fonts
  static_dir: _/fonts

- url: /images/(.*\.(gif|png|jpg))$
  static_files: images/\1    # assuming you put your images in a directory called 'images'
  upload: images/.*\.(gif|png|jpg)$

- url: /.*
  script: not_found.php    # if not_found.php (custom 404 handler) exists.  otherwise, just serve index.php