Examine source code of Lukall

{
  "manifest_version": 2,
  "name": "Safe Search Engine - Lukall",
  "short_name": "Lukall",
  "description": "Safe Search Engine for kids, students and society.",
  "version": "1.1.0",
  "author": "Lukall",
  "icons": {
    "128": "icon.png"
  },
  "browser_action": {
    "default_icon": "icon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://lukall.com/*"
      ],
      "js": [
        "content-script.js"
      ]
    }
  ],
  "permissions": [
    "https://*.lukall.com/"
  ],
  "chrome_settings_overrides": {
    "homepage": "https://www.lukall.com",
    "search_provider": {
      "name": "lukall",
      "search_url": "https://www.lukall.com/search?q={searchTerms}",
      "keyword": "lukall",
      "favicon_url": "https://www.lukall.com/favicon.icon",
      "is_default": true,
      "encoding": "UTF-8"
    }
  },
  "chrome_url_overrides": {
    "newtab": "index.html"
  }
}