How to make a "create post" feature similar to Medium

Guys, do you have any ideas how to make a rich-text form submission possible? I want to make it possible so people can publish their stories (kind of like on Medium), but right now the form submission only allows normal text, so people can’t really publish their stories the way they’d like them to.

Any thoughts, ideas?


Here is my site Read-Only: LINK
(how to share your site Read-Only link)