Examine source code of Custom Shortcut Manager

{
  "manifest_version": 2,
  "name": "Custom Shortcut Manager",
  "version": "1.0",
  "description": "Create and manage custom shortcuts for your favorite websites.",
  "permissions": [
    "storage"
  ],
  "browser_action": {
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{62100df5-d8f4-4544-8066-eee686e68707}"
    }
  }
}