Formatting overhaul

[MilesCranmer]

• Adds pre-commit to run formatting automatically. Also applies formatting rules to markdown and yaml.
• Replace all unnecessary instances of import with using to increase idiomaticness

[github-actions]

Benchmark Results

	master	d49e85b...	t[master]/t[d49e85b...]
search/multithreading	23 ± 1.1 s	21.8 ± 0.37 s	1.06
search/serial	30.1 ± 0.77 s	29.7 ± 0.76 s	1.01
utils/best_of_sample	0.792 ± 0.25 μs	1.08 ± 0.48 μs	0.732
utils/check_constraints_x10	12.2 ± 3.1 μs	12.2 ± 3.1 μs	1.01
utils/compute_complexity_x10/Float64	2.25 ± 0.12 μs	2.25 ± 0.12 μs	1
utils/compute_complexity_x10/Int64	2.26 ± 0.12 μs	2.27 ± 0.12 μs	0.996
utils/compute_complexity_x10/nothing	1.49 ± 0.1 μs	1.49 ± 0.11 μs	0.999
utils/optimize_constants_x10	28.4 ± 6.2 ms	29.8 ± 6.7 ms	0.954
time_to_load	1.32 ± 0.0078 s	1.34 ± 0.0046 s	0.988

Benchmark Plots

A plot of the benchmark results have been uploaded as an artifact to the workflow run for this PR.
Go to "Actions"->"Benchmark a pull request"->[the most recent run]->"Artifacts" (at the bottom).