Update link to GitHub issues page (#21409)

Have people pick an issue template instead of creating an empty issue

index.html

@@ -19,7 +19,7 @@
 <table border="0" id="rgb">
 	<tr><td><a class="button" id="r" href="https://github.com/ytdl-org/youtube-dl/blob/master/README.md#readme">Documentation</a></td></tr>
 	<tr><td><a class="button" id="g" href="download.html">Download</a></td></tr>
-	<tr><td><a class="button" id="main-support" href="https://github.com/ytdl-org/youtube-dl/issues/new">Support</a></td></tr>
+	<tr><td><a class="button" id="main-support" href="https://github.com/ytdl-org/youtube-dl/issues/new/choose">Support</a></td></tr>
 	<tr><td><a class="button" id="y" href="https://github.com/ytdl-org/youtube-dl/">Develop</a></td></tr>
 	<tr><td><a class="button" id="b" href="about.html">About</a></td></tr>
 </table>