Submodule plots is in `__all__` but not imported in `__init__.py`

[SkirOwen]

Hi,

This might be deliberate but it seems that the submodule plots is not imported in the __init__.py but is included in __all__.
I can see there are some optional dependencies for some of the functions but their imports are only inside the concerned functions.

That means that if someone wants to use the plots submodule they would need to explicitly import it, which seems a bit strange when the documentation has this:

import cmocean
cmocean.plots.plot_gallery()

Which currently gives:

AttributeError: module 'cmocean' has no attribute 'plots'

[kthyng]

I'm sorry I saw these come in initially but forgot to reply!

It was intentional to not import plots in __init__ since it has extra dependencies. However, you are correct that then the docs don't demonstrate the you'd need to explicitly import it. If you can untangle how to build the docs, I'd appreciate you fixing that! It'll probably be awhile before I get to it otherwise, but I'll do it next time I'm working on them.