Examine source code of Fat Startpage

{
  "manifest_version": 2,
  "name": "Fat Startpage",
  "version": "1.2",
  "description": "A simplistic configurable start/new tab page for firefox",
  "chrome_settings_overrides": {
    "homepage": "index.html"
  },
  "chrome_url_overrides": {
    "newtab": "index.html"
  },
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{6cfc5f29-28a8-4e4d-b0ee-e9bb8b051a09}"
    }
  }
}