Examine source code of Come on Ecosia! (unofficial)

{
  "name": "Come on Ecosia!",
  "description": "An extension which makes your default search ecosia and redirects you to ecosia.org if you go to Google, Bing, Yahoo, Yandex, Baidu, Sogou and more",
  "version": "1.6",
  "manifest_version": 2,
  "icons": {
    "48": "Come_on_Ecosia_48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.google.com/*",
        "https://www.google.ca/*",
        "https://www.google.com.hk/*",
        "https://www.google.com.au/*",
        "https://www.google.co.in/*",
        "https://www.google.co.jp/*",
        "https://www.google.com.ar/*",
        "https://www.google.com.vn/*",
        "https://www.google.com.mx/*",
        "https://www.google.de/*",
        "https://www.google.fr/*",
        "https://www.google.hu/*",
        "https://www.google.it/*",
        "https://www.google.nl/*",
        "https://www.google.pl/*",
        "https://www.google.pt/*",
        "https://www.bing.com/*",
        "https://*.yahoo.com/*",
        "https://www.yahoo.co.jp/*",
        "https://yandex.ru/*",
        "https://yandex.com/*",
        "https://www.aol.com/*",
        "https://www.aol.co.uk/*",
        "https://*.ask.com/*",
        "https://www.egerin.com/*",
        "https://startpage.com/*",
        "https://www.webcrawler.com/*",
        "https://yippy.com/*",
        "https://yippy.com/*",
        "https://qwant.com/*",
        "https://lite.qwant.com/*",
        "https://duckduckgo.com/*",
        "https://html.duckduckgo.com/*",
        "https://www.swisscows.com/*",
        "https://www.baidu.com/*",
        "https://www.sogou.com/*"
      ],
      "js": [
        "redirect.js"
      ]
    }
  ],
  "chrome_settings_overrides": {
    "homepage": "https://www.ecosia.org/",
    "search_provider": {
      "name": "Ecosia Search",
      "keyword": "ecosia",
      "search_url": "https://www.ecosia.org/search?q={searchTerms}&addon=firefox&addonversion=4.0.4",
      "favicon_url": "https://cdn.ecosia.org/assets/images/ico/favicon.ico",
      "suggest_url": "https://ac.ecosia.org/?q={searchTerms}&type=list&mkt=__MSG_@@ui_locale__",
      "encoding": "UTF-8",
      "is_default": true
    }
  },
  "browser_action": {
    "default_icon": "Come_on_Ecosia!.png",
    "default_popup": "extension.html"
  }
}