feat: repl improvements

[devsnek]

Several changes aiming to improve legibility and functionality. Currently WIP pending fixes to LSP completion & additions to rustyline.

Peek.2024-08-12.22-34.mp4

[sigmaSd]

I personally don't like the In Out prompts, I think the current style is nicer.

[jeff-hykin]

I'm personally conflicted. I support it, as I think this design is more functional. I can think of plently of times where the extra newline would have helped when pasting multiline inputs. But also I agree it looks less visually appealing compared to the simple prompt right now.

Not to bikeshed, but just to give an option: maybe a symbol for output and a symbol for input, instead of words, would be more appealing. Ex

<1:
>1:

1:
1;

1:
1*

[ry]

Looks great