updated readme, contributing guidelines, and added a notebook #496

Job	Run time
build-docs (3.8)	3m 41s
build-mpi (3.9)	2m 11s
build-jax (3.8)	1m 49s
build-mpi (3.10)	1m 44s
build-jax (3.9)	58s
build-numpy (3.8, short)	1m 44s
build-jax (3.10)	54s
build-torch (3.8)	2m 15s
build-numpy (3.8, optimize)	1m 56s
build-torch (3.9)	2m 40s
build-numpy (3.8, multivariate)	1m 25s
build-torch (3.10)	2m 24s
build-numpy (3.8, optimize-experimental)	2m 4s
build-numpy (3.9, short)	1m 53s
build-numpy (3.9, optimize)	1m 58s
build-numpy (3.9, multivariate)	1m 33s
build-numpy (3.9, optimize-experimental)	2m 21s
build-numpy (3.10, short)	1m 46s
build-numpy (3.10, optimize)	1m 54s
build-numpy (3.10, multivariate)	1m 33s
build-numpy (3.10, optimize-experimental)	2m 16s
	40m 59s

Provide feedback