Examine source code of MyCesarDomain

{
  "manifest_version": 2,
  "name": "MyCesarDomain",
  "version": "1.1",
  "description": "Encodes the domain name of the current site with a Caesar key",
  "homepage_url": "https://github.com/mdn/webextensions-examples/tree/master/bookmark-it",
  "icons": {
    "16": "icons/laurier-16.png",
    "24": "icons/laurier-24.png",
    "32": "icons/laurier-32.png",
    "64": "icons/laurier-64.png",
    "128": "icons/laurier-128.png",
    "256": "icons/laurier-256.png",
    "512": "icons/laurier-512.png"
  },
  "permissions": [
    "bookmarks",
    "tabs"
  ],
  "browser_action": {
    "default_icon": "icons/laurier-256.png",
    "default_title": "MyCesarDomain"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{4fb0cb89-6b00-432c-8511-f48e498a43e2}"
    }
  }
}