implement dot for higher-dimensional arrays with Ix2 #684

Job	Run time
docs/nightly	23s
nostd/thumbv6m-none-eabi/stable	21s
miri	10m 56s
cross_test/i686-unknown-linux-gnu/stable	2m 8s
format/nightly	15s
cargo-careful	1m 53s
clippy/stable	20s
Pass MSRV values to other jobs	4s
cross_test/s390x-unknown-linux-gnu/stable	8m 2s
blas-msrv	52s
tests/beta	3m 1s
tests/stable	2m 43s
tests/nightly	2m 54s
tests/1.87.0	2m 35s
conclusion	2s
	36m 29s

Provide feedback