Examine source code of Basic Twitch Chat

{
  "applications": {
    "gecko": {
      "id": "{4D91E5D3-4850-402A-8884-3282E182C6C8}",
      "strict_min_version": "57.0"
    }
  },
  "author": "Frank Dreßler",
  "manifest_version": 2,
  "name": "Basic Twitch Chat",
  "version": "1.2resigned1",
  "description": "Allows you to change Twitch chat's appearance.",
  "permissions": [
    "*://twitch.tv/*",
    "*://*.twitch.tv/*",
    "contextMenus",
    "storage",
    "tabs",
    "activeTab",
    "webNavigation"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}