Examine source code of idFont

{
  "manifest_version": 3,
  "name": "idFont",
  "version": "1.0",
  "description": "Identify fonts on any page via the context menu.",
  "browser_specific_settings": {
    "gecko": {
      "id": "idfont@ikornii.dev",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  },
  "permissions": [
    "menus",
    "activeTab"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "type": "module"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "content.css"
      ]
    }
  ],
  "icons": {
    "48": "assets/icons/icon-48.png",
    "96": "assets/icons/icon-96.png"
  }
}