Examine source code of Quick Copy URL

{
  "manifest_version": 2,
  "name": "Quick Copy URL",
  "version": "1.3",
  "description": "Quickly copy the URL of your current tab with a click",
  "homepage_url": "https://github.com/vantezzen/quick-copy-url",
  "icons": {
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png"
  },
  "permissions": [
    "activeTab",
    "clipboardWrite"
  ],
  "browser_action": {
    "default_icon": {
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png"
    },
    "default_title": "Copy URL",
    "default_popup": "popup/index.html"
  },
  "background": {
    "scripts": [
      "background/main.js"
    ]
  },
  "commands": {
    "copy-url": {
      "suggested_key": {
        "default": "Ctrl+Shift+U"
      },
      "description": "Copy the URL of your current tab"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{40043094-aad5-4868-b0da-840ed60e7a40}"
    }
  }
}