Example of reading data/header with io.fits.read is broken

[wtbarnes]

In the docs, we have the following example of how to read the data and header directly from a file using sunpy.io.fits.read,

[data,header] = sunpy.io.fits.read(filename)

There are a few problems here.

1. If you have 2 HDUs, this returns the first to data and the second to header, obviously not the intended behavior.
2. You can use the hdus kwarg to select only a specific HDU but it turns out this is broken because the rest of the function expects an HDUList and after we slice it, we don't cast it back to an HDUList so everything after this explodes in fun and unexpected ways.
3. Even accounting for the first two problems, this function returns a list of data,header pairs, not a list of data and headers so you get a ValueError when trying to return this to a tuple as above. Fixing items 1 and 2, this example could be amended to,

data, header = sunpy.io.fits.read(filename)[0]