Examine source code of Youtube Zen

{
  "manifest_version": 2,
  "name": "Youtube Zen",
  "version": "1.0.3",
  "description": "Boosts productivity by removing certain distracting elements on youtube.",
  "homepage_url": "https://github.com/Zackyization/youtube-zen",
  "browser_action": {
    "browser_style": true,
    "default_title": "Youtube Zen",
    "default_popup": "popup/youtube-zen-popup.html"
  },
  "background": {
    "scripts": [
      "background/youtube-zen-background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "js": [
        "content_scripts/youtube-zen.js"
      ],
      "css": [
        "css/youtube-home.css"
      ],
      "run_at": "document_idle",
      "all_frames": true
    }
  ],
  "icons": {
    "48": "icons/youtube_zen_icon_square.svg",
    "96": "icons/youtube_zen_icon_square.svg"
  },
  "permissions": [
    "*://*.youtube.com/*",
    "storage",
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{c3b671a3-5b0b-409a-a4a0-95e81d3cc06d}"
    }
  }
}