Hi Hurtworldians!
The upload side of the workshop integration is now live in the Hurtworld Map SDK.
This should give you some time to get those maps uploaded and ready to go for the client and server release later this month which will allow clients and servers to automatically download your maps on startup.
We are still working through some teething permissions issues on the server side, however we should have a working build in the devtest beta branch in the next few days.
For details on how to use the uploader, check out the Wiki page here:
http://hurtworld.gamepedia.com/Uploading_to_Steam_Workshop
Happy modding!