Examine source code of FontSpy

{
  "manifest_version": 3,
  "name": "FontSpy",
  "description": "Hover to reveal font details & download in 1 click - the ultimate font inspector for devs & designers. Part of the DesignSpy Toolkit.",
  "version": "1.0",
  "author": "CyberLab",
  "browser_specific_settings": {
    "gecko": {
      "id": "fontspy@designspy.toolkit",
      "strict_min_version": "109.0"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "activeTab",
    "scripting",
    "downloads",
    "storage"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "background": {
    "service_worker": "background.js",
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_title": "FontSpy"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ]
}