[ENH] Add back documentation about byte order / endianness documentation

[maxnoe]

Is your feature request related to a problem? Please describe.

Older versions of the documentation contained mentions of endianness / byte order in the numpy and buffer parts.

These have gone away and I cannot find any mention of byte order / endian issues mentioned in the docs.

Describe the solution you'd like.

Add back information on what cython supports with respect to e.g. non-native byte order numpy arrays

Describe alternatives you've considered.

No response

Additional context

No response

[da-woods]

Do you have a link (possibly to an archive site or anything like that)? I tried searching the commit history for a few likely words and didn't come up with anything.

Is it possible that it might have been a third-party document? I do remember seeing some useful unofficial guides to the finer details of some of the Numpy support.

[maxnoe]

I found this: https://cython-docs2.readthedocs.io/en/stable/src/tutorial/numpy.html

which looked like an old cython documentation, but seems like third party tutorials?

Anyways, the point is that cython code fails with errors like "big-endian buffer not supported on little-endian compiler" which is not documented anywhere now it seems.

We encounter this error regularly, since a data format that is extremely prevalent in astronomy mandates big-endian storage.

[da-woods]

I've added a little more detail in #6181. Mainly about options like cast rather than endianness specifically, but hopefully it's an improvement.