add sphinx-toggleprompt

[jurasofish]

• Closes add toggle for prompts in example code in docs #1095
• I am familiar with the contributing guidelines
• Tests added
• Updates entries to docs/sphinx/source/api.rst for API changes.
• Adds description and name entries in the appropriate "what's new" file in docs/sphinx/source/whatsnew for all changes. Includes link to the GitHub Issue with :issue:`num` or this Pull Request with :pull:`num`. Includes contributor name and/or GitHub username (link with :ghuser:`user`).
• New code is fully documented. Includes numpydoc compliant docstrings, examples, and comments where necessary.
• Pull request is nearly complete and ready for detailed review.
• Maintainer: Appropriate GitHub Labels and Milestone are assigned to the Pull Request and linked Issue.

[jurasofish]

It's not formatting the "Out[19]:" correctly. Will fix

[jurasofish]

This is good for review now

[wholmgren]

LGTM. Thanks @jurasofish. @pvlib/pvlib-maintainer feel free to merge if you're happy with this approach

[cwhanse]

Thanks again @jurasofish

[kandersolar]

Looking at the latest pages on RTD, it seems like comments might get dropped when hiding the prompts? For example the Simple ModelChain example. It seems desirable to me to keep the comments when copy/pasting example code -- is there a way to configure it so comment lines stick around?

[jurasofish]

It doesn't hide comments generally, for example see https://docs.python.org/3/tutorial/controlflow.html#for-statements

That modelchain example is a tricky case because the IPython formatting has placed the comment outside an input prompt and formatted it the same as an output, so it's indistinguishable from an output.

The way to tackle it would be to get the upstream IPython formatter to give it a unique style which could then be hidden. Might need changes in pygments, not sure. Or, the IPython formatter could put comments next to "In [xx]:" cells like any normal input.