Examine source code of XRef - URL Shortener

{
  "manifest_version": 2,
  "name": "XRef - URL Shortener",
  "version": "1.0",
  "description": "XREF URL Shortener extension",
  "homepage_url": "https://www.xref.ws/",
  "icons": {
    "48": "icons/xref-logo.svg",
    "96": "icons/xref-logo.svg"
  },
  "permissions": [
    "activeTab",
    "contextMenus",
    "clipboardWrite",
    "storage",
    "notifications"
  ],
  "browser_action": {
    "default_icon": "icons/xref-logo.svg",
    "default_title": "XRef Shorten URL",
    "default_popup": "html/menu_popup.html"
  },
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ]
    }
  ]
}