biff.graph: structure your data model as a queryable graph

The next Biff 2 library is ready to go: biff.graph

biff.graph makes your codebase more understandable/maintainable by helping you split up your code for reading/deriving data into small independent chunks. "Data-oriented dependency injection" is a term I've used to describe the approach.

biff.graph is a lightweight clone/variant of Pathom. I'm a huge fan of Pathom and wanted to include it in Biff by default, however it is a bit of a heavy abstraction and I was concerned if the benefits would be worth the learning effort for people working on small projects.

So biff.graph is an attempt to provide something similar to Pathom in as few lines of code as possible (~600 to be specific, with ~200 for the query engine). You still have to learn the same conceptual model, but learning what exactly it's doing under the hood should be easier. The tradeoff is that biff.graph has less functionality--most significantly there's no query planner, so biff.graph isn't as intelligent about how it executes your queries as Pathom is.