Specify `kaleido` as an optional requirement

[tmarice]

Kaleido is an optional requirement for Plotly's static image export functionality, but currently there's no way to specify this dependency relationship. E.g. we're using pip-tools and even though kaleido isn't our project's direct dependency, we still have to specify it in the requirements.in file:

plotly==4.14.3
kaleido==0.1.0  # Plotly's dependency for static image export

Is it possible to add Kaleido to setuptools extras_require section, in order to be able to write something like pip install plotly[kaleido]?

[nicolaskruchten]

@jonmmease thoughts?

[gvwilson]

Hi - we are trying to tidy up the stale issues and PRs in Plotly's public repositories so that we can focus on things that are still important to our community. Since this one has been sitting for several years, I'm going to close it; if it is still a concern, please add a comment letting us know what recent version of our software you've checked it with so that I can reopen it and add it to our backlog. Thanks for your help - @gvwilson