Migrate JuliaActuary/Learn/Benchmarks?

[alecloudenback]

Any opposition to moving the benchmarks from https://github.com/JuliaActuary/Learn/tree/master/Benchmarks (website view: https://juliaactuary.org/benchmarks/) to this repository?

[MatthewCaseres]

I didn't see this when it was open apologies for lateness.

Our setup right now runs every benchmark on every commit. So we need/want to refactor to make CI runs more granular before scaling the number of benchmarks.

Probably wouldn't port the life modeling problem from JuliaActuary but IRR and black-scholes we would port and the issue remains open.