I pushed the beta (the steamworkshop-compatible build) to the main branch and took the game out of Early Access. Most workshop-related features should work, but if they don't you can also revert back to the non-workshop build in the steam game properties betas dropdown (it should be called old_stable).
If you have any bugs related to this new version don't hesitate to drop a message in the discussion board. I've also included a link in the map category (in main menu) to the custom maps tutorial.