Goals and non-goals
For a crate like this, I think it's super important to lay out goals and non-goals. Let's figure out what they are!
Some sources of inspiration for goals and non-goals:
I think what's absolutely vital for this crate is to not re-invent the wheel. We don't want to replace configure, at most I think what we should consider this crate as is a layer on-top of it to make it more convenient to use.
The name of the crate is confy, like "comfy"/"comfortable". Which means we can sacrifice some flexibility to make the experience for the end-user nicer.
Absolute non-goals would for example be: inventing a new config format, support all config formats out there or even a comprehensive feature list like having multiple config files where fields from one overwrite fields in another.
Viper looks like something that tries to do everything which is not something I think we should replicate or even try to emulate.