I was thinking there could be a forum channel filled with resources that other people could find useful. There could be tags such as "CSS/JS", "Gadget", "Fix", or "Miscellaneous".
#Channel proposal: #resources
stoic prism
hoary rose
A wiki would be a better fit for this kind of thing - the closest that exists currently is https://dev.miraheze.org
void jolt
Putting a small snippet like this on the dev wiki requires writing a lot of documentation and future maintenance, also often extensions are not available and the default skin is vector which means most people won't be able to preview stuff that is made for other skins like citizen
On discord you can just simply share a screenshot of how the result of the CSS looks like; on the wiki it's not that easy