Count Julia docstrings separately from code

[ericphanson]

Closes #76

This PR uses JuliaSyntax to count Julia code. Split out from #79 since I think this part is better scoped and easier to land by itself.

This should be non-breaking from an API and an serialization perspective, although obviously the counts change.

TODO:

• Tests for the code-counting functionality

[giordano]

I only had a cursory look, also because I'm not much familiar with JuliaSyntax, but this looks awesome!

Should we have some tests to ensure we can still read V1 of the schema?

[ericphanson]

https://github.com/JuliaEcosystem/PackageAnalyzer.jl/pull/86/files#diff-3b9314a6f9f2d7eec1d0ef69fa76cfabafdbe6d0df923768f9ec32f27a249c63R407 should cover that, since it was serialized out w/ V1 of the schema (and the file isn't updated in this PR).

BTW: should this be a breaking or feature release for PackageAnalyzer? It doesn't break serialization but the actual counts do change, since now we count docstrings.

[giordano]

#86 (files) should cover that, since it was serialized out w/ V1 of the schema (and the file isn't updated in this PR).

Uh, ok!

BTW: should this be a breaking or feature release for PackageAnalyzer? It doesn't break serialization but the actual counts do change, since now we count docstrings.

Even though I don't think this is technically breaking, keeping consistent numbers within a major release is probably a safe choice!