Accept 'exit' as an alias for /exit #1867

Describe the feature or problem you'd like to solve

exit is the standard to close a shell (e.g. bash) - copilot tries to use this as a prompt

Proposed solution

It is highly unlikely one ever want to use a prompt that reads exit but it easily happens if one is used to using exit to close a terminal/ssh session to type it and submit it to copilot...

It would generally be good to ask the user in case of one word only if it really wants to submit it... ls / ll or similar are other easily to get wrong patterns...

Example prompts or workflows

No response

Additional context

No response