Create benchmark suite

[Luis-Varona]

We should create a benchmark suite similarly to what Graphs.jl has done.

[Luis-Varona]

This may prove a useful dataset for tests: https://sparse.tamu.edu/.

[tmigot]

These two packages might be useful:
https://github.com/JuliaSparse/MatrixMarket.jl
https://github.com/JuliaSmoothOptimizers/SuiteSparseMatrixCollection.jl

[Luis-Varona]

Ooo, thanks, @tmigot! This is certainly unrelated to JOSS, but it's been on my to-do list for a while, and I definitely want to get to it soon. These two packages look like they could help for sure 🙂