Workaround `options` docs not being rendered in RTD
Workaround `options` docs not being rendered in RTD

Cause & solution: https://github.com/rtfd/readthedocs.org/issues/855#issuecomment-261337038

I decided to simply move the docs to the class's docstring.
That's easier and more portable.

jmb/geopy,geopy/geopy