Threw something quick together based on nodebb-plugin-spoilers, I also looked into extending the existing markdown plugin using the extension support the parser has, but didn't really succeed. Would be great if we could just add markdown-it extensions in the admin panel to extend the syntax, cuz there are plenty existing ones
SOLVED Navbar Text
Is there an option to show text in the navigation bar instead or along with the icons?
Create your own theme based on nodebb-theme-persona by making a copy of it. Give it a suitable name. Remove the classes
/templates/partials/menu.tplin your theme folder. That does the job
@JasperNL thank you that did the trick