Un éditeur plus avancé devrait être ici ?

[Mittineague]

I’m thinking this link needs to be more widely publicized.

Word-wrap or line length oddities

Learn more about markdown at https://commonmark.org/help

EDIT
Maybe try this plugin by @Steven ?

Formatting toolbar

Add some formatting options to your discourse posts : center a text or an image, align to the right, justify, colors, underline, etc. It’s easy to use and it will provide some options to embellish your posts.