Examine source code of YT Mini Player Button Restorer

{
  "manifest_version": 3,
  "name": "YouTube Mini Player Button Restorer",
  "version": "1.1.1",
  "description": "Brings back the missing mini player button on YouTube with the same 'i' key functionality.",
  "host_permissions": [
    "*://*.youtube.com/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "styles.css"
      ],
      "run_at": "document_end"
    }
  ],
  "action": {
    "default_popup": "popup.html",
    "default_title": "YouTube Mini Player Button Restorer"
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "youtube-mini-player-button-restorer@felixweissenbach.net",
      "strict_min_version": "142.0"
    }
  },
  "web_accessible_resources": [
    {
      "resources": [
        "icons/miniplayer-icon.svg"
      ],
      "matches": [
        "*://*.youtube.com/*"
      ]
    }
  ],
  "author": "Felix Weissenbach (cloned from https://github.com/Harryrosestudios/YouTube-Mini-Player-Button-Restorer)",
  "homepage_url": "https://github.com/Felix-Weissenbach/Youtube-Mini-Player-Button-Restorer"
}