Update README.md

adding WSS exceptions for dummies

Author: donbright

README.md

@@ -55,7 +55,13 @@ understand it. You can do this by installing it as accepted certificate, or by
 using that same certificate for a HTTPS connection to which you navigate first
 and approve. Browsers generally don't give you the "trust certificate?" prompt
 by opening a WSS socket with invalid certificate, hence you need to have it
-accept it by either of those two methods.
+accept it by either of those two methods. 
+
+The ports may be considered as distinguishing connections by the browser,
+for example, if your website url is https://my.local:8443 and your WebSocket 
+url is wss://my.local:8001, first browse to https://my.local:8001, add the 
+exception, then browse to https://my.local:8443 and add another exception.
+Then an html page served over :8443 will be able to open WSS to :8001
 
 If you have a commercial/valid SSL certificate with one or more intermediate
 certificates, concat them into one file, server certificate first, then the