Add a way to disable the prompt

[rtpg]

This is part of work to simplify this nushell PR. Clearing out the prompt removes a reference to the stack, letting us avoid a copy

[stormasm]

@rtpg can you please add in a example that shows this working... Thanks !

[stormasm]

@rtpg as far as the example it can be as simple as the

https://github.com/nushell/reedline/blob/main/examples/basic.rs

but call it disable_prompt.rs

[fdncred]

@rtpg as far as the example it can be as simple as the

https://github.com/nushell/reedline/blob/main/examples/basic.rs

but call it disable_prompt.rs

I don't really understand what you're saying here. Can you add an example and some test to ensure this behavior works in the future?

[fdncred]

unresponsive.