Users have questions about the way the editor extension model works. Can we please have an explanation?

• Please see attached screenshot:

• Where does this list of available plugins come from?
• Can users add their own plugins to this list somehow?
• When a plugin is selected (see screenshot), what kind of artifacts make up the 'plugin' and where do they come from?
• When a plugin is selected and installed, what changes in Dev Spaces? (i.e. are there changes to the devfile, to some Persistent Volume, to some Custom Resource, etc.)
• How does the workspace 'remember' that plugin has been installed when it is stopped and restarted?