Examine source code of start-page

{
  "manifest_version": 2,
  "name": "start-page",
  "description": "A minimal new tab start page",
  "version": "0.2.0",
  "icons": {
    "16": "icons/16.png",
    "32": "icons/32.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "permissions": [
    "activeTab",
    "search",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "start-page@pruizlezcano",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "chrome_url_overrides": {
    "newtab": "newtab.html"
  },
  "browser_action": {
    "default_title": "Save bookmark",
    "default_popup": "popup.html"
  }
}