Add from_emcee inline examples (#638)
Add from_emcee inline examples (#638)

* Add from_emcee examples

Added examples in from_emcee docstring using the python scripts in
`doc/usage_examples` folder.
Created the `usage_examples`.

* Improve emcee's autocorr functions explanation

Differences between emcee versions pointed out and explained.

* Simplify code using from_dict

* modify explanation

* from_emcee inline examples

Docs break but I do not understand why

* Docs seem to work now

No idea why

* Remove examples folder

* pylint fix

* Remove subjective language

* Grammar correction

arviz-devs/arviz,arviz-devs/arviz,arviz-devs/arviz,arviz-devs/arviz