prompt: how to add newlines to body

There seems to be no way of adding newlines to the body of the commit. No way to really use for long commit messages as is, since a one line huge body isn't that nice.

## Expected Behavior

Shift+enter or `\n` should work.

Even better would be auto wrapping to say 80 characters, so that one could write it out naturally, but the prompt would cut it down to lines.

## Current Behavior

Enter (and shift+enter) submits and `\n` gets printed as is 😢

## Affected packages
* [ ] cli
* [ ] core
* [x] prompt
* [ ] config-angular