There are a lot of code categories on Rosetta code with no Crystal examples.
An easy way to increase Crystal’s profile on the site, and in the coding world overall, is for people to provide the missing examples. The easiest way to do this is to just translate the Ruby version in each category, as a start.
Doing this would not only up Crystal’s profile, it would also be a good exercise for people (newbies, et al) looking to do something tangible with Crystal. This will surely benefit Crystal, by being more visible for more categories, and acting as coding tutorials too.
The instructions for adding new code is on the above site. It’s may be initially confusing at first (it was for me), but once you do it once it makes sense (it could be made much simpler though).