Examine source code of SoundCloud Control

{
  "manifest_version": 2,
  "name": "SoundCloud Control",
  "description": "Controla la reproducción de SoundCloud sin cambiar de pestaña.",
  "version": "1.7.0",
  "icons": {
    "16": "icon/16.png",
    "32": "icon/32.png",
    "48": "icon/48.png",
    "96": "icon/96.png",
    "128": "icon/128.png"
  },
  "permissions": [
    "tabs",
    "scripting",
    "downloads",
    "storage",
    "*://soundcloud.com/*",
    "*://*.soundcloud.com/*",
    "*://backend1.tioo.eu.org/*",
    "*://api-v2.soundcloud.com/*",
    "*://api.github.com/*"
  ],
  "commands": {
    "toggle-playback": {
      "suggested_key": {
        "default": "Ctrl+Shift+6"
      },
      "description": "Alternar reproducción en SoundCloud"
    },
    "previous-song": {
      "suggested_key": {
        "default": "Ctrl+Shift+5"
      },
      "description": "Ir a la pista anterior en SoundCloud"
    },
    "next-song": {
      "suggested_key": {
        "default": "Ctrl+Shift+7"
      },
      "description": "Ir a la pista siguiente en SoundCloud"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{65009ef0-e104-4198-b842-f828ad527a1a}",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "SoundCloud Control",
    "default_popup": "popup.html"
  },
  "options_ui": {
    "open_in_tab": false,
    "page": "options.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.soundcloud.com/*",
        "*://soundcloud.com/*"
      ],
      "run_at": "document_start",
      "js": [
        "content-scripts/content.js"
      ]
    }
  ]
}