Examine source code of YouTube Thumbnail Downloader

{
  "manifest_version": 3,
  "name": "YouTube Thumbnail Downloader",
  "version": "1.1.3",
  "description": "Adds a button on YouTube thumbnails to view, download, or copy the max-resolution thumbnail (maxresdefault.jpg).",
  "author": "Ryan Aby",
  "homepage_url": "https://github.com/ryanaby/youtube-thumbnail-downloader",
  "icons": {
    "48": "icon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.youtube.com/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "activeTab",
    "scripting",
    "clipboardWrite"
  ],
  "host_permissions": [
    "*://i3.ytimg.com/*",
    "*://www.youtube.com/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "yt-thumb@ryanaby.dev",
      "strict_min_version": "109.0"
    }
  }
}