Examine source code of Playlist Insights

{
  "manifest_version": 3,
  "version": "1.0",
  "browser_specific_settings": {
    "gecko": {
      "id": "{b9b64c77-1ed0-4dfc-85d6-1e44d27b5b0a}"
    }
  },
  "name": "Playlist Insights",
  "description": "A browser extension that provides insights about video playlists.",
  "content_scripts": [
    {
      "matches": [
        "*://www.youtube.com/*",
        "*://youtube.com/*"
      ],
      "js": [
        "assets/src/main.js"
      ]
    }
  ],
  "icons": {
    "48": "assets/icons/48.png",
    "64": "assets/icons/64.png"
  },
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "assets/icons/16.png",
      "24": "assets/icons/24.png",
      "32": "assets/icons/32.png"
    }
  },
  "permissions": [
    "tabs"
  ]
}