DOC: Create "version added" documentation instructions to developer guide

[venaturum]

Location of the documentation

Added to bottom of https://www.staircase.dev/en/latest/development/guide/code.html

Note: You can check the latest versions of the docs on master here.

Documentation problem

Features added to the code (new methods or parameters), should be accompanied by a "new in version ..." piece in the docstring.

The developer guide needs a section which asks developers to use this sphinx directive when contributing to code, and provide small docstring examples for method and parameter.

Suggested fix for documentation

These additions can be automatically generated by sphinx https://www.sphinx-doc.org/en/master/usage/restructuredtext/directives.html?highlight=versionadded#directive-versionadded

See method example here https://github.com/pandas-dev/pandas/blob/v0.20.2/pandas/core/frame.py#L1495

See parameter example here https://github.com/pandas-dev/pandas/blob/v0.20.2/pandas/core/generic.py#L568

[gourcool]

Can you assign this issue to me

[venaturum]

@gourcool, sure thing. I think if you leave the comment "take" it will automatically assign it to you too.

[venaturum]

let me know if you need a hand or guidance at any stage