Examine source code of IconBar

{
  "manifest_version": 2,
  "name": "IconBar",
  "version": "1.3",
  "description": "Sidebar with bookmark icons that matches your browser's theme.",
  "homepage_url": "https://github.com/diemtea/Firefox-IconBar",
  "icons": {
    "48": "icon.png"
  },
  "background": {
    "scripts": [
      "sidebar.js"
    ],
    "persistent": false
  },
  "sidebar_action": {
    "default_icon": {
      "48": "icon.png"
    },
    "default_title": "IconBar",
    "default_panel": "index.html"
  },
  "permissions": [
    "bookmarks",
    "storage"
  ],
  "web_accessible_resources": [
    "index.html",
    "sidebar.js",
    "style.css"
  ],
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "browser_specific_settings": {
    "gecko": {
      "id": "{9dba9848-1289-4662-ac96-487a72c7e9fe}"
    }
  }
}