Added Win10 bash setup guide

Added a setup/installation guide for an experimental Win10 Bash installation based on my setup experience. I Linked it under the already existing Win 10 preperation guide.

doc/prepare.md

@@ -239,6 +239,8 @@ Start the PostgreSQL database
 sudo service postgresql start
 ```
+For a Windows 10 Bash Setup Guide of the GDK please follow this [guide](./set-up-winbash.md)
+
 For some common troubleshooting steps for Windows 10 GDK installs please refer to [Troubleshooting](./howto/troubleshooting.md)
 ### Other platforms