"start new chat" option for /archive and /delete

[StephenCarboni]

Simple addition. Instead of

› 1. No, don't archive      Return to the current session
  2. Yes, archive and exit  Archive this session now

We have:

› 1. No, don't archive
  2. Yes, archive and exit
  3. Yes, archive and start new chat

I think the help text would be repetitive for the third option; perhaps all the help text could be elided? Maybe the main text for the options could be expanded:

› 1. No, don't archive and return to the current session
  2. Yes, archive this session now and exit
  3. Yes, archive this and start a new chat