threads notes link added

doc/Design_notes/modules/zmapServer.html

@@ -4,8 +4,8 @@
 <p>The zmapServer module exist to provide concurrent thread base interfaces to external databases.  It uses the zmapThread module.
 </p>
 --- put this in a table and extend ---<br />
-zmapServer is the front end that is used by zmapView etc to request data.<br />
-zmapServerProtocolHandler interfaces between zmapServer and the thread base servers.<br />
+zmapServerProtocolHandler is the front end that is used by zmapView etc to request data.<br />
+zmapServer interfaces between zmapServerProtocolHandler and the thread base servers.<br />
 acedb/, DAS, and pipe/ are the servers that run in these threads.
 <br />
 <br />
@@ -13,6 +13,7 @@ acedb/, DAS, and pipe/ are the servers that run in these threads.
 <h3>Related pages</h3>
 <p><a href="Design_notes/modules/zmapView.shtml#reqdata">zmapView</a> contains some notes about requesting data from pipeServer modules and other issues.</p>
 <p><a href="Design_notes/modules/pipeServer.shtml">pipeServer</a> details usage of that module.</p>
+<p><a href="Design_notes/notes/slaveThread.shtml">Threads</a> some notes about thread startup and shutdown.</p>
 </fieldset>
 
 <fieldset><legend>Servers and Threads</legend>