docs(python): Update plot docs to refer to docstrings

[henryharbeck]

Closes #17503

Have aligned these files with py-polars/docs/source/reference/dataframe/style.rst, so hopefully it should work the same. Leaving as draft so I can build the docs locally and double check.

[MarcoGorelli]

thanks @henryharbeck

Have aligned these files with py-polars/docs/source/reference/dataframe/style.rst, so hopefully it should work the same. Leaving as draft so I can build the docs locally and double check.

I presume you did this and that it works as intended?

[henryharbeck]

Hi @MarcoGorelli - yes I did.
Thanks for confirming - apologies, I should've updated the PR description.

For Series.plot, I used the autoproperty directive instead of autoaccessorattribute (which all the other Series attributes use), as it displays the return type. Useful I figured particularly when it is not a Polars type.

[MarcoGorelli]

good one @henryharbeck