Examine source code of Music Importer

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "version": "1.0",
  "description": "__MSG_extensionDescription__",
  "icons": {
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "permissions": [
    "activeTab",
    "downloads",
    "storage"
  ],
  "browser_action": {
    "default_popup": "popup/popup.html",
    "default_icon": {
      "48": "icons/icon-48.png"
    }
  },
  "options_ui": {
    "page": "options/options.html",
    "open_in_tab": true
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{a6fa301d-7142-45eb-9dc3-1ca483265fd8}"
    }
  }
}