Added note to README about port - fixes #41

Author: csharpfritz

README.md

@@ -15,6 +15,8 @@ cd csharp_with_csharpfritz
 docker-compose up
 ```
 
+The notebooks run by default on network port 8888. 
+
 ## Community
 
 This project has adopted the code of conduct defined by the [Contributor Covenant](http://contributor-covenant.org/) to clarify expected behavior in our community. For more information, see the [.NET Foundation Code of Conduct](http://www.dotnetfoundation.org/code-of-conduct).