Examine source code of Beautify

{
  "manifest_version": 2,
  "name": "beautify",
  "version": "1.4",
  "description": "Make the Cambridge dictionary distraction free!",
  "author": "ggerico",
  "icons": {
    "48": "icons/book_48px.png",
    "96": "icons/book_96px.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.cambridge.org/dictionary/english-chinese-traditional/*"
      ],
      "js": [
        "beautify.js",
        "ch-lookup.js"
      ],
      "css": [
        "style.css"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "permissions": [
    "https://www.moedict.tw/uni/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{8b47a86f-7b2f-456b-9611-a04ad893a32b}"
    }
  }
}