Examine source code of Dad Joke

{
  "manifest_version": 2,
  "name": "Dad Joke",
  "description": "A Simple New Tab To Laugh At Dad Jokes!",
  "version": "2.0",
  "icons": {
    "16": "icon/16.png",
    "32": "icon/32.png",
    "48": "icon/48.png",
    "128": "icon/128.png"
  },
  "permissions": [
    "bookmarks"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{e1c4022c-3a75-4ee3-99b0-7fcacdc9b1c8}",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "chrome_url_overrides": {
    "newtab": "newtab.html"
  }
}