Better organise documentation
I know this would be a big job, but it would be really useful if the documentation could be organised better. Function documentation is organised by source file and it often is not self-evident in which file a given function would be written. Browsing through the sourcefiles exposes the user to some of the backend implementation. Furthermore, there is no clear distinction between low-level and high-level features within each module. Much of this criticism applies to Nim docs as a whole (I don't find the default tool is particularly good).

Relatedly, the tutorials section could probably use expansion and additional documentation could likely be given at the top of each file. Of course, I fully appreciate that this would be a lot of work (and generally less interesting than implementing new features).