Examine source code of Tab Group Manager Lite

{
  "manifest_version": 2,
  "name": "Tab Group Manager",
  "version": "1.0",
  "description": "Create and manage tab groups easily",
  "permissions": [
    "tabs",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{06825226-7d24-4ffc-8862-c4befe4f82bd}",
      "strict_min_version": "112.0"
    }
  },
  "icons": {
    "64": "icon64.png",
    "128": "icon128.png"
  },
  "browser_action": {
    "default_title": "Tab Group Manager",
    "default_popup": "popup.html"
  }
}