Examine source code of Selector Gadget Zen

{
  "manifest_version": 3,
  "name": "Selector Gadget Zen",
  "version": "1.0.0",
  "description": "Inspect elements and copy their CSS or XPath selectors.",
  "permissions": [
    "activeTab",
    "storage",
    "scripting"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "action": {
    "default_title": "Toggle Selector Inspector"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "css": [
        "styles.css"
      ],
      "js": [
        "content_script.js"
      ]
    }
  ],
  "icons": {
    "48": "icons/icon_48x48.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{0b519bcc-d48f-4fe3-91dd-d4eaec0d9368}"
    }
  }
}