Add reference to RustCrypto/XOFs to the root README (#873) #235

Job	Run time
minimal-versions / minimal-versions	25s
set-msrv / set-msrv	4s
test (1.85.0)	22s
build (stable, wasm32-unknown-unknown)	11s
build (stable, thumbv7em-none-eabi)	12s
build (1.85.0, wasm32-unknown-unknown)	20s
build (1.85.0, thumbv7em-none-eabi)	20s
test (stable)	18s
	2m 12s

Provide feedback