Examine source code of Is it WordPress?

{
  "manifest_version": 2,
  "name": "Is it WordPress?",
  "version": "1.2",
  "description": "Right-click on any link to check if it's a WordPress site and see the version",
  "author": "Shawn DeWolfe - Web321 Marketing Ltd.",
  "homepage_url": "https://web321.co",
  "browser_specific_settings": {
    "gecko": {
      "id": "is-it-wordpress@web321.co",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "contextMenus",
    "activeTab",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "icons": {
    "48": "icon.png",
    "96": "icon.png"
  }
}