Examine source code of Youtube Player Improved

{
  "manifest_version": 2,
  "name": "Youtube Player Improved",
  "version": "1.3.1",
  "description": "Set a preferred video quality, set a start volume, block volume scroll, mute hover previews, prevent Shorts from looping, auto-expand the player, control captions, float a mini player, hide info cards & end screens, keep original titles/descriptions/chapters, and prevent accidental Shorts scrolling on YouTube.",
  "author": "Youtube Player Improved",
  "browser_specific_settings": {
    "gecko": {
      "id": "youtube-player-improved@local.addon",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "96": "icons/icon96.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "storage",
    "*://*.youtube.com/*",
    "*://*.youtube-nocookie.com/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png"
    },
    "default_title": "Youtube Player Improved"
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.youtube.com/*",
        "*://m.youtube.com/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "content.css"
      ],
      "run_at": "document_idle",
      "all_frames": false
    },
    {
      "matches": [
        "*://www.youtube.com/embed/*",
        "*://youtube.com/embed/*",
        "*://www.youtube-nocookie.com/embed/*",
        "*://youtube-nocookie.com/embed/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "content.css"
      ],
      "run_at": "document_idle",
      "all_frames": true
    }
  ]
}