Examine source code of Maximize Video

{
  "description": "__MSG_extDescription__",
  "manifest_version": 2,
  "name": "__MSG_extName__",
  "version": "0.0.24",
  "homepage_url": "https://github.com/ettoolong/MaximizeVideo",
  "icons": {
    "16": "icon/icon.svg",
    "32": "icon/icon.svg",
    "48": "icon/icon.svg",
    "64": "icon/icon.svg",
    "96": "icon/icon.svg"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "MaximizeVideo@ettoolong",
      "strict_min_version": "66.0"
    }
  },
  "developer": {
    "name": "Ett Chung",
    "url": "https://github.com/ettoolong/MaximizeVideo"
  },
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*",
        "file:///*"
      ],
      "js": [
        "js/content-script.js"
      ],
      "css": [
        "css/maximizeVideo.css"
      ],
      "all_frames": true,
      "run_at": "document_start"
    },
    {
      "matches": [
        "https://www.youtube.com/*"
      ],
      "js": [
        "js/ytb.js"
      ],
      "css": [
        "css/ytb.css"
      ],
      "all_frames": false,
      "run_at": "document_start"
    }
  ],
  "browser_action": {
    "browser_style": true,
    "default_title": "__MSG_extDescription__",
    "default_icon": "icon/icon_b.svg"
  },
  "permissions": [
    "http://*/*",
    "https://*/*",
    "file:///*",
    "storage"
  ],
  "default_locale": "en",
  "options_ui": {
    "page": "options.html",
    "open_in_tab": false,
    "browser_style": true
  },
  "commands": {
    "maximizeVideo": {
      "description": "__MSG_execute__"
    }
  }
}