chore: add documentation guidelines

[Valentin271]

This PR adds general guidelines on how to write documentation for Ratatui.

I based the guidelines off of #386 and #443.

[codecov]

Codecov Report

Merging #447 (3cec62e) into main (14eb6b6) will decrease coverage by 0.40%.
Report is 7 commits behind head on main.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main     #447      +/-   ##
==========================================
- Coverage   90.42%   90.03%   -0.40%     
==========================================
  Files          40       40              
  Lines       11081    11127      +46     
==========================================
- Hits        10020    10018       -2     
- Misses       1061     1109      +48     

see 8 files with indirect coverage changes

[joshka]

Thanks for adding this.

A couple of suggested extra guidelines for your consideration:

• generally hide imports and use the prelude / wildcard imports to keep things concise. E.g.:

/// # use ratatui::{prelude::*, widgets::*};

• generally use syles expressed using the Stylize trait shortcuts instead of the more verbose styles. E.g.:

let style = Style::new().red().bold();
// not
let style = Style::default().fg(Color::Red).add_modifier(Modifiers::BOLD);

[joshka]

See comments at #448 for some more discussion about discoverability of docs.

[mindoodoo]

Will be nice to have this in.

Could you please also add a mention that ratatui tends to attract beginner rust users and that that should be kept in mind when writing documentation for it.

[Valentin271]

I think I addressed most of what you said in c74f918. Let me know if there are anything else.

[joshka]

Changes LGTM

changes were made

[joshka]

Thanks for the PR @Valentin271 !