docs: add tutorials to Sphinx build

[dacoex]

Add
https://github.com/pvlib/pvlib-python/tree/master/docs/tutorials
to
http://wholmgren-pvlib-python-new.readthedocs.org/en/docfixes/index.html#

maybe with a link to the nbviewer.
there's also a ipython sphinx plugin
http://matplotlib.org/sampledoc/extensions.html#ipython-sessions
https://github.com/ipython/ipython/tree/master/IPython/sphinxext

[wholmgren]

There's already a link to an nbviewer page with the tutorials.

"This documenation focuses on providing a reference for all of the modules and functions available in pvlib-python. For examples of how to use pvlib-python, please see the tutorials."

Inline code in documentation and IPython sphinxext is a separate issue.

[dacoex]

There's already a link to an nbviewer page with the tutorials.
Yes, but from which page in the docs at RTD can this be found?

[wholmgren]

Not sure what exactly you want me to address here...

#22 is a PR to fix documentation problems raised in issue #16 (and more). This is what I quoted from, since this is what you linked to originally.

The official documentation for pvlib-python is http://pvlib-python.readthedocs.org/en/latest/ and it too contains a link to the tutorials.

[dacoex]

Not sure what exactly you want me to address here...
Nevermin. overlooked that sentence
"This documenation focuses on providing a reference for all of the modules and functions available in pvlib-python. For examples of how to use pvlib-python, please see the tutorials."

I was used to check only the ToC