Examine source code of Auto theme changer

{
  "background": {
    "scripts": [
      "main.js",
      "background.js"
    ],
    "persistent": false
  },
  "version": "1.1",
  "description": "Automatically changes your theme at startup to any theme you have downloaded. Default theme, dark theme, and light theme will not be selected.",
  "manifest_version": 2,
  "name": "Auto theme changer",
  "summary": "Changes your theme automatically when you load Firefox.",
  "permissions": [
    "management"
  ],
  "icons": {
    "48": "logo.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "Autothemechanger@myextension1.com"
    }
  }
}