Update README.md

Co-authored-by: Ronald Barendse <[email protected]>

Author: Paul Johnson

README.md

@@ -47,7 +47,7 @@ $ dotnet tool install --global Umbraco.Docs.Preview.App
 
 Or check out the source at: [https://github.com/umbraco/UmbracoDocs.Preview](https://github.com/umbraco/UmbracoDocs.Preview).
 
-Once installed, navigate to your local clone of the UmbracoDocs repository and run the command `umbracodocs`. This will start a local webserver (the URL will be shown), which you can open in your browser and view the rendered documentation.
+Once installed, navigate to your local clone of the UmbracoDocs repository and run the command `umbracodocs`. This will start a local webserver that's listening on `http://localhost:5000` and `https://localhost:5001` by default (the actual URLs will be shown), which you can open in your browser to view the rendered documentation.
 
 # Contributing [![contributions welcome](https://img.shields.io/badge/contributions-welcome-brightgreen.svg?style=flat)](https://github.com/umbraco/UmbracoDocs/issues) [![GitHub contributors](https://img.shields.io/github/contributors/umbraco/UmbracoDocs.svg)](https://GitHub.com/umbraco/UmbracoDocsgraphs/contributors/)
 We :heart: valuable contributions from everyone who is willing to help. It does not matter to us if it's something trivial like correcting spelling mistakes, raising an issue or writing a tutorial! Every little bit of help counts and it all helps make Umbraco easier to use, for everyone.