Add a way for preloading default/suggested Matrix rooms

For Fedora KDE, we currently ship Konversation with a preloaded configuration to make it easy for people to join Fedora KDE's channels and various support channels. As part of Fedora's transition of real-time chat from primarily IRC to primarily Matrix, we would like to ship NeoChat for this purpose and have it pre-configured to suggest these rooms for users to interact with us.

I'm not exactly sure what kind of workflow makes sense for this with NeoChat, perhaps a "suggested rooms" page when you first create/sign-in your Matrix account into NeoChat so that they can join right away? Or maybe automatic join is possible?