bpo-30052: Link `bytes` & `bytearray` to stdtypes not functions (GH-1271)

bpo-30052: Link `bytes` & `bytearray` to stdtypes not functions  (GH-1271)

Builtin container types have two potential link targets in the docs:

- their entry in the list of builtin callables
- their type documentation

This change brings `bytes` and `bytearray` into line with other
container types by having cross-references default to linking to
their type documentation, rather than their builtin callable entry.