doc: fix confusing reference in net.md

PR-URL: https://github.com/nodejs/node/pull/12247
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Sam Roberts <vieuxtech@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Alexey Orlenko <eaglexrlnk@gmail.com>

doc/api/net.md

@@ -874,7 +874,8 @@ Additional options:
   [`socket.setTimeout(timeout)`][] after the socket is created, but before
   it starts the connection.
 
-Here is an example of a client of the previously described echo server:
+Following is an example of a client of the echo server described
+in the [`net.createServer()`][] section:
 
 ```js
 const net = require('net');