Examine source code of YouTube Button Controller

{
  "manifest_version": 3,
  "name": "YouTube Button Controller",
  "version": "2.4.0",
  "description": "Enhanced YouTube controller with keyboard shortcuts, volume control, speed adjustment, and advanced features",
  "author": "Alireza Talebi",
  "homepage_url": "https://github.com/AlirezaTalebi/Youtube-Buttons-Controller-Firefox-Extention",
  "browser_specific_settings": {
    "gecko": {
      "id": "{bdeebc30-5928-43be-936c-0bfcaac4f06a}",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "tabs",
    "storage"
  ],
  "host_permissions": [
    "*://*.youtube.com/*",
    "*://youtube.com/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*",
        "*://youtube.com/*",
        "*://m.youtube.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_start",
      "all_frames": false
    }
  ],
  "action": {
    "default_popup": "popup.html",
    "default_icon": "images/youtube.png"
  },
  "commands": {
    "play-pause": {
      "suggested_key": {
        "default": "Ctrl+Alt+P"
      },
      "description": "Play/Pause video"
    },
    "next-video": {
      "suggested_key": {
        "default": "Ctrl+Alt+Right"
      },
      "description": "Next video"
    },
    "previous-video": {
      "suggested_key": {
        "default": "Ctrl+Alt+Left"
      },
      "description": "Previous video"
    },
    "toggle-mute": {
      "suggested_key": {
        "default": "Ctrl+Alt+M"
      },
      "description": "Toggle mute"
    },
    "volume-up": {
      "suggested_key": {
        "default": "Ctrl+Alt+Up"
      },
      "description": "Volume up"
    },
    "volume-down": {
      "suggested_key": {
        "default": "Ctrl+Alt+Down"
      },
      "description": "Volume down"
    },
    "speed-up": {
      "suggested_key": {
        "default": "Ctrl+Alt+Period"
      },
      "description": "Increase playback speed"
    },
    "speed-down": {
      "suggested_key": {
        "default": "Ctrl+Alt+Comma"
      },
      "description": "Decrease playback speed"
    },
    "skip-forward": {
      "suggested_key": {
        "default": "Ctrl+Alt+F"
      },
      "description": "Skip forward 10 seconds"
    },
    "skip-backward": {
      "suggested_key": {
        "default": "Ctrl+Alt+B"
      },
      "description": "Skip backward 10 seconds"
    },
    "stop-video": {
      "suggested_key": {
        "default": "Ctrl+Alt+S"
      },
      "description": "Stop video"
    },
    "restart-video": {
      "suggested_key": {
        "default": "Ctrl+Alt+R"
      },
      "description": "Restart video from beginning"
    }
  },
  "icons": {
    "48": "images/youtube.png"
  }
}