We have now added the ability to upload KML files directly to cloud.gaiagps.com/upload (in addition to GPX). You can also upload pictures along with tracks, directly on the website.
If you use Gaia GPS on iOS or Android, these uploads will automatically sync to your devices via GaiaCloud, for use in your adventures. You can also use this feature without owning the app, so you can share your tracks and view them on the website.