Example of file write uses an unsupported type cf64_le

[sandersa-nist]

When running the example for data storage on the readme.md page, there is an error

data = np.zeros(1024, dtype=np.complex64) uses an unsupported type in sigmffile.SigMFFile the code around line 554 needs to be updated to include
if "64" in dtype:
sample_size = 8

[jacobagilbert]

Thanks for the report @sandersa-nist - currently 64 types are not supported, and there is an open issue to include support for these (#196) so I'm going to close this as a duplicate to that. If you'd like to explain your use case there it will put more pressure on us to get that supported :)