Update index.html

- added GitHub sponsors link.

donate/index.html

@@ -46,6 +46,7 @@ <h2 class="title center" id="genki-Donate">Donate</h2>
         <p><a href="https://github.com/SethClydesdale">Seth Clydesdale</a> created Colloquial Kansai Dictionary to help make it easier to look up and review points for Colloquial Kansai Japanese. As an open source developer, my only source of income for my works are donations. So if you found this project helpful and would like to support my work, please see below for the different ways that you can contribute.</p>
 
         <ul>
+          <li>Sponsor me on <a href="https://github.com/sponsors/SethClydesdale"><strong>GitHub</strong></a>.</li>
           <li>Send me a tip via <a href="https://paypal.me/sethc95/"><strong>PayPal</strong></a>.</li>
           <li>Buy me a coffee via <a href="https://ko-fi.com/sethc95"><strong>Ko-fi</strong></a>.</li>
           <li>Buy me a gift from my Amazon Wishlist: <a href="https://www.amazon.com/hz/wishlist/ls/S7YILFHYK0IZ"><strong>US</strong></a> | <a href="https://www.amazon.jp/hz/wishlist/ls/31FKBIJPAGBAL"><strong>JP</strong></a>.</li>