Examine source code of Bookmark Tag Manager

{
  "manifest_version": 2,
  "name": "Bookmark Tag Manager",
  "version": "1.2",
  "description": "Advanced Bookmark Manager with Tagging System for Firefox",
  "browser_specific_settings": {
    "gecko": {
      "id": "tagmanager@aldomauro.extension",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  },
  "permissions": [
    "activeTab",
    "bookmarks",
    "storage",
    "tabs"
  ],
  "icons": {
    "16": "assets/icons/icon-16.png",
    "32": "assets/icons/icon-32.png",
    "48": "assets/icons/icon-48.png",
    "128": "assets/icons/icon-128.png"
  },
  "browser_action": {
    "default_title": "Bookmark Tag Manager",
    "default_popup": "popup/popup.html",
    "default_icon": {
      "16": "assets/icons/icon-16.png",
      "32": "assets/icons/icon-32.png",
      "48": "assets/icons/icon-48.png",
      "128": "assets/icons/icon-128.png"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "web_accessible_resources": [
    "dashboard/dashboard.html",
    "dashboard/dashboard.js",
    "dashboard/dashboard.css",
    "assets/images/edit.svg",
    "assets/images/delete.svg",
    "assets/images/star.svg",
    "assets/images/dashboard.png",
    "assets/icons/icon-48.png"
  ]
}