CI: Add comment

Author: amotl

.github/workflows/main.yml

@@ -73,6 +73,7 @@ jobs:
             netsh winsock reset
 
             # Disable IPv6.
+            # https://superuser.com/questions/1545288/disable-ipv6-connectivity-on-windows-without-restarting-the-computer
             netsh interface teredo set state disabled
             netsh interface ipv6 6to4 set state state=disabled undoonstop=disabled
             netsh interface ipv6 isatap set state state=disabled