add a code of conduct #269

Job	Run time
lint	1m 17s
test (ubuntu-latest, 3.10, jax)	5m 37s
test (ubuntu-latest, 3.10, tensorflow)	6m 23s
test (ubuntu-latest, 3.10, torch)	4m 11s
test (ubuntu-latest, 3.11, jax)	6m 29s
test (ubuntu-latest, 3.11, tensorflow)	5m 35s
test (ubuntu-latest, 3.11, torch)	4m 21s
test (windows-latest, 3.10, jax)	11m 50s
test (windows-latest, 3.10, tensorflow)	10m 24s
test (windows-latest, 3.10, torch)	13m 18s
test (windows-latest, 3.11, jax)	12m 5s
test (windows-latest, 3.11, tensorflow)	13m 38s
test (windows-latest, 3.11, torch)	13m 15s
	1h 48m 23s

Provide feedback