Examine source code of Copy ShortURL

{
  "name": "__MSG_extensionName__",
  "description": "__MSG_extensionDescription__",
  "author": "Fred Wenzel",
  "homepage_url": "http://copy-shorturl.rtfd.org",
  "version": "5.5.0",
  "default_locale": "en",
  "applications": {
    "gecko": {
      "id": "jid0-ODIKJS9b4IT3H1NYlPKr0NDtLuE@jetpack",
      "strict_min_version": "63.0"
    }
  },
  "icons": {
    "16": "data/img/icon-16.png",
    "32": "data/img/icon-32.png",
    "48": "data/img/icon-48.png",
    "64": "data/img/icon-64.png"
  },
  "manifest_version": 2,
  "permissions": [
    "activeTab",
    "clipboardWrite",
    "contextMenus",
    "notifications",
    "storage",
    "<all_urls>"
  ],
  "background": {
    "page": "data/html/background-page.html"
  },
  "commands": {
    "shorten-page-url": {
      "suggested_key": {
        "default": "Ctrl+Shift+L"
      },
      "description": "Copy ShortURL of the current page"
    }
  },
  "browser_action": {
    "default_icon": "data/img/icon.svg",
    "theme_icons": [
      {
        "light": "data/img/icon-white.svg",
        "dark": "data/img/icon-black.svg",
        "size": 32
      }
    ],
    "default_area": "navbar",
    "default_title": "__MSG_browserAction_label__"
  },
  "options_ui": {
    "page": "data/html/options.html",
    "browser_style": true
  }
}