merging lib with custom lib

[IogaMaster]

Is your feature request related to a problem? Please describe.

I want to be able to use the functions and utils I write in the lib/ directory to be usable in my modules.

Describe the solution you'd like

Describe alternatives you've considered

Additional context

[phaer]

There's some discussion on design of this feature in https://github.com/numtide/blueprint/pull/16

[voruti]

What's a currently available alternative/workaround?