Mention downloads in README.

Author: dsvensson

README.md

@@ -2,7 +2,11 @@
 
 Some very sharp corners.
 
-## Introduction:
+## Introduction
 
  * [misc/cfg/camquake.cfg](misc/cfg/camquake.cfg)
  * https://www.youtube.com/@jogihoogi1
+
+## Downloads
+
+Latest build for Windows, macOS and Linux can be found as a logged in GitHub user in the [Actions](https://github.com/qw-ctf/camQuake/actions) tab.