Examine source code of ytb-playlist-sort

{
  "manifest_version": 2,
  "name": "ytb-playlist-sort",
  "version": "1.0",
  "description": "Sorts youtube playlists based on duration",
  "icons": {
    "48": "icons/time-48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "js": [
        "main.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{7437d018-eef0-459d-b56c-70ec51347d47}"
    }
  }
}