Docs on rendering pipeline

[NaLiJa]

Hi there, Many thanks for making this engine available, it looks very interesting! Do you perhaps have some minimal docs on the rendering pipeline? I wonder whether it might be possible to integrate rmlui lib into your engine ( a low level ui library). It is rendered directly on a window context (see e.g. https://github.com/mikke89/RmlUi/tree/master/Backends). Do you perhaps have any advice which would be the preferred place to inject this into supernova? Perhaps in subsystem/renderer? Thanks for your great work!