[Doc] Adding support for versioned documentation

[asfimport]

Per this GitHub issue: #4016

The request: API docs for previous PyArrow versions as a drop-down link in the sidebar of this page: https://arrow.apache.org/docs/python/api.html

I often work in multiple environments with PyArrow versions ranging from 0.8.0 to 0.12+, and the core Python API has changed quite a bit version-to-version so code occasionally no longer works. It can be difficult to hunt down the corresponding changes in each version. Versioned docs similar to pandas and other popular libraries would be excellent.

Reporter: Helen Ngo

Related issues:

• [Doc] Host different released versions of the documentation + version switcher (is a clone of)

_{Note: This issue was originally created as ARROW-5067. Please see the migration documentation for further details.}

[asfimport]

Wes McKinney / @wesm:
We mainly need to find a place to host the versioned documentation. I am not sure how scalable our approach in https://github.com/apache/arrow-site is

[asfimport]

Joris Van den Bossche / @jorisvandenbossche:
I am going to close this as a duplicate of ARROW-13260. And I am working on this (should normally land for the 6.0 release)