Examine source code of Material New Tab

{
  "manifest_version": 3,
  "name": "Material New Tab",
  "version": "1.0.0",
  "description": "A custom new tab page using the latest Material Design Guidelines.",
  "chrome_url_overrides": {
    "newtab": "index.html"
  },
  "permissions": [
    "geolocation"
  ],
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "action": {
    "default_title": "Material New Tab",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      },
      "id": "mnt@k4ustu3h"
    }
  }
}