DOC: Update docstring of DataFrame/Series .equals() to explain the behavior with indices

[datapythonista]

Some work and some discussion happened at #19213.

df1.equals(df2) returns a single boolean value on whether the two dataframes contain the same values and indices. This includes types for the data, but not for the indices.

The docstring should be improved to follow all our standards, including:

• A See Also section that at least links to .eq()
• Parameters
• Examples
• Notes with the mentioned behavior about indices

[seantchan]

@datapythonista If no one's working on this, can I claim it? I'm new to contributing and am still working my way around the workflow but am happy to help out if possible!

[datapythonista]

Sure @seantchan , that's a great first issue if you're starting. Let me know if you need help.

[seantchan]

Thanks Marc - working on it now. The docstring is all typed up, just reviewing it now and setting up the dev environment.