document bc desktops in containers

[johrstrom]

Through the arduous journey in this discourse topic and this issue I've found that we support running containerized bc desktops out of the box.

This ticket is to document that fact and should include

• definition file required (currently only MATE is known)
• submit file required (currently only singularity is known)
• what you'll need to modify and why
• common issues encountered

┆Issue is synchronized with this Asana task by Unito

[vallerul]

May i know if we have an update to this?
I have been looking at ways to mate Desktop app work with Singularity container, and it has not been easy.