Initializing Iceberg's repository list

I believe that there is a way one can add one or more repositories to Iceberg’s list of local repositories, so that when one opens a new image (new = just dowloaded using the Pharo launcher), the repository is already present in Iceberg’s list.   Stéph showed me how to do this once, but I’ve lost the configuration file (or whatever it was) and can’t now figure out where to put it.

Can someone point me to the documentation?

        Andrew