How to correctly use nim doc when a project has unimported modules

[haxscramper]

If runnable examples and other things are not important the simpler set of 
targets would still include the result JSON shema and a way for other tools to 
make sense of it. Some cleanup elements can still be omitted, like runnable 
examples triggered directly during doc generation, but in terms of design it is 
just mixing in phases 1,2,4 into one block.