Add a gitattributes file to specify LF line endings #320

Job	Run time
Miri	1m 6s
Clippy (stable)	31s
Check (stable)	18s
Rustfmt (stable)	12s
Test Suite	4m 23s
Test Suite (stable)	36s
Test Suite (--no-default-features)	4m 21s
Test Suite (ubuntu-latest)	38s
Test Suite (stable, --no-default-features)	39s
Test Suite (windows-latest)	1m 35s
Test Suite (--features track-caller)	4m 19s
Test Suite (stable, --features track-caller)	39s
Test Suite (macOS-latest)	1m 9s
Test Suite (--features auto-install)	4m 17s
Test Suite (stable, --features pyo3)	37s
Test Suite (stable, --features auto-install)	35s
Test Suite (stable, --all-features)	35s
Test Suite (beta)	34s
Test Suite (beta, --no-default-features)	35s
Test Suite (beta, --features track-caller)	37s
Test Suite (beta, --features pyo3)	36s
Test Suite (beta, --features auto-install)	34s
Test Suite (beta, --all-features)	36s
Test Suite (nightly)	45s
Test Suite (nightly, --no-default-features)	43s
Test Suite (nightly, --features track-caller)	43s
Test Suite (nightly, --features pyo3)	44s
Test Suite (nightly, --features auto-install)	44s
Test Suite (nightly, --all-features)	44s
	34m 25s

Provide feedback