Mention where to look for UDP support

Author: moritz

doc/Type/IO/Socket/INET.pod6

@@ -9,6 +9,8 @@ class IO::Socket::INET does IO::Socket {}
 
 C<IO::Socket::INET> provides TCP sockets, both the server and the client side.
 
+For UDP support, please see L<IO::Socket::Async>.
+
 Here is an example of a very simplistic "echo" server that listens on
 C<localhost>, port C<3333>: