Examine source code of Numbers & Counting

{
  "manifest_version": 2,
  "name": "Numbers & Counting",
  "version": "1.0",
  "description": "Popup game to practice Vietnamese numbers and counting words in English – ideal for beginners and children learning basic numeracy.",
  "icons": {
    "48": "numbers_icon.png"
  },
  "browser_action": {
    "default_popup": "index.html",
    "default_title": "Numbers & Counting"
  },
  "permissions": [],
  "browser_specific_settings": {
    "gecko": {
      "id": "{caf814f0-d48f-408f-8235-d2cce1699220}",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  }
}