Officially replace linenoise in Nim's stdlib

[AndreiRegiani]

This should be the endgame of nimline.

Once this module is stable it definitely can get into the stdlib replacing linenoise in rstdlib module, see some of the issues:

inim-repl/INim#7
nim-lang/Nim#5795

Even without these issues it's not nice to have non-pure libs in the stdlib.

[h3rald]

Wow! Thanks! And I didn't even officially publicize this properly yet!

For now I am currently only using it internally for the shell component of my min programming language (https://min-lang.org).

Note that there are still some issues with nimline, e.g. no proper emacs/vim key bindings and currently I am only managing only ONE line. If you hit the end of the terminal it just won't let you type anything else.

That been said, I guess some docs are in order anyway...

[h3rald]

@AndreiRegiani Alright, here are some reference docs. Do you think that's enough?