Examine source code of Streamlink Helper

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "description": "__MSG_extensionDescription__",
  "version": "1.3.0",
  "default_locale": "en",
  "applications": {
    "gecko": {
      "id": "streamlink.firefox.helper@gmail.com",
      "strict_min_version": "56.0a1"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "streamlinkviashortcut.js"
      ]
    }
  ],
  "commands": {
    "launch-streamlink": {
      "suggested_key": {
        "default": "Ctrl+Alt+S"
      },
      "description": "Launches streamlink with the current page"
    }
  },
  "permissions": [
    "menus",
    "nativeMessaging",
    "tabs"
  ]
}