Examine source code of startpage

{
  "manifest_version": 2,
  "name": "startpage",
  "short_name": "startpage",
  "version": "1.12.0",
  "description": "Overrides the browsers newtab page with a custom startpage.",
  "author": "etacarinaea",
  "browser_specific_settings": {
    "gecko": {
      "id": "{219d2cc9-3c2f-45a9-a55b-6c04d6c097f3}"
    }
  },
  "icons": {
    "48": "img/icon48.png",
    "96": "img/icon96.png",
    "128": "img/icon128.png",
    "192": "img/icon192.png"
  },
  "chrome_url_overrides": {
    "newtab": "index.html"
  },
  "background": {
    "scripts": [
      "js/update.js",
      "js/update-config.js"
    ]
  },
  "permissions": [
    "storage"
  ]
}