Add support for "Hint" feature in Suite Guide

[tomasklim]

It would be nice to extend our guide markdown to support hints which are available in Gitbook. Right now, we have "Tips" and "Warnings" just with icons and plain text. It would be nice to be able to highlight it.

Now (text after bulb):

Idea:

Gitbook reference: https://docs.gitbook.com/editing-content/rich-content/with-command-palette#hints-and-callouts Guide support list: https://github.com/trezor/trezor-suite-guide

Dev info: Probably this addon can be used. https://github.com/sergioramos/remark-hint

cc @b-irving

[b-irving]

Great idea - properly formatted hints and callouts would be much more effective when highlighting the most important information for the user.