Add documentation on `wrap_err` vs `wrap_err_with` #258

Job	Run time
Check (stable)	16s
Clippy (stable)	34s
Rustfmt (stable)	17s
Miri	1m 35s
Test Suite	3m 30s
Test Suite (ubuntu-latest)	49s
Test Suite (--no-default-features)	3m 38s
Test Suite (stable)	57s
Test Suite (windows-latest)	1m 34s
Test Suite (--features track-caller)	3m 33s
Test Suite (macOS-latest)	1m 17s
Test Suite (stable, --no-default-features)	49s
Test Suite (--features auto-install)	5m 14s
Test Suite (stable, --features track-caller)	46s
Test Suite (stable, --features pyo3)	50s
Test Suite (stable, --features auto-install)	1m 0s
Test Suite (stable, --all-features)	50s
Test Suite (beta)	59s
Test Suite (beta, --no-default-features)	50s
Test Suite (beta, --features track-caller)	46s
Test Suite (beta, --features pyo3)	48s
Test Suite (beta, --features auto-install)	56s
Test Suite (beta, --all-features)	52s
Test Suite (nightly)	1m 0s
Test Suite (nightly, --no-default-features)	1m 0s
Test Suite (nightly, --features track-caller)	58s
Test Suite (nightly, --features pyo3)	1m 0s
Test Suite (nightly, --features auto-install)	1m 3s
Test Suite (nightly, --all-features)	1m 0s
	38m 41s

Provide feedback