add a hint in the doc that we need ORPort to be defined.

people seem to not be doing it lately.


svn:r4153

doc/tor-doc.html

@@ -268,6 +268,7 @@ you will need to copy torrc.sample to torrc first. Look for them in
         <tt>\Application Data\</tt><i>username</i><tt>\tor\torrc</tt>
         on Windows.</li>
 </ul>
+Make sure to define at least Nickname and ORPort.
 Create the DataDirectory if necessary, and make
 sure it's owned by the user that will be running tor. Fix your system
 clock so it's not too far off. Make sure name resolution works.