[DOC] #noqa comment appears in docs

Brief Description of Fix

A #noqa:E501 comment in the docstring from encode_categorical() appears in the docs. The #noqa:E501 comment exists due to a long url in the docstring which angers pycodestyle.

I’m currently not familiar enough with reStructuredText or Sphinx to know how to solve this issue.

A quick search of the published docs shows a number of #noqa comments that may not be desired.

Relevant Context

• Link to documentation page
• Link to exact file to be edited

[bdice]

I had this problem in a package I maintain, and we solved it by moving #noqa to the line where the triple quote ends, like this:

"""A fancy docstring.

It'd be a shame if we ruined this beautiful docstring with a long
`StackOverflow`_ link.

.. _StackOverflow: https://stackoverflow.com/questions/38884538/python-pandas-find-all-rows-where-all-values-are-nan
"""  # noqa: E501

Example from my package’s code: https://github.com/glotzerlab/freud/blob/0dae9cee1423ae9a0ed8923547e44c41b93b5672/freud/order.pyx#L188-L194

[bdice]

@ericmjl I see what you did there. 😆 Glad to see that worked for you. Good luck!