You can always put your solutions on the GitHub if you want. You just need to download it. But OutSystems doesn't work with GitHub where you can see more than one version of the same file. 

But still, you can download various solutions/omls (is better to download omls, but you can still share with other people to try) and upload them to Git Hub.

Have a look at this post to know better

https://www.outsystems.com/forums/discussion/82791/the-best-way-to-use-all-opportunities-of-git/

Kind Regards,

Márcio