Doesn't compile when UIElements built-in package is disabled

[Razenpok]

I don't know for sure, but you could probably add com.unity.modules.uielements to package dependencies for auto-resolution, or maybe just note that UIElements package is required. Thanks for the package tho, really cool.

[neon-age]

Oh, I didn't knew it can be disabled. This seem to be related to the fact that assembly is currently 'runtime' - see #27.