Does anyone know of, or work with, a cross-platform ASP.NET Core content management system with decent documentation? From my research, Orchard Core and Piranha CMS seem to be the most mature, but the documentation is severely lacking. Orchard Core has some detailed docs, but I don't see anything to help me get started.

For background I've been working with Umbraco for about 6 years now, and when I started there wasn't much documentation, but there was enough to get started. Once I had something up and running, I just started studying the source code. I've thought about building my own CMS, but would rather rely on a project that is well tested.