Definition of `dtype` int (int=int32) in documentation is inconsistent with HDMF (int=int8)

[ehennestad]

See HDMF:
https://hdmf-schema-language.readthedocs.io/en/latest/description.html#attribute-specification-keys

vs NWB:
https://schema-language.readthedocs.io/en/latest/description.html#attribute-specification-keys