DOC: Version information in headline / menubar
Example
https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.drop.html

It would be nice to show the pandas version this documentation is related to.
The version string could be placed somewhere in the head, e.g. beside the horizontal menu bar.

The Python docs does this. There you can see everytime the current version.
Python also offers a drop down menu to select a specific docs version. I think this is overhead and not needed for pandas.