DOC: add pivot_table note to dropna doc
- [ ] closes #47447 
- [ ] [Tests added and passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#writing-tests) if fixing a bug or adding a new feature
- [ ] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [ ] Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
- [ ] Added an entry in the latest `doc/source/whatsnew/vX.X.X.rst` file if fixing a bug or adding a new feature.

Thanks for the pull request @Mehgarg 

The pandas documentation is generated automatically from markdown files and docstring (documentation in the code). We never edit the final html files directly.

I think the changes you want to implement should be done to this docstring instead: https://github.com/pandas-dev/pandas/blob/main/pandas/core/frame.py#L6427

Can you revert this html file you're creating and edit the docstring please? Let me know if you need help Hello @Mehgarg! Thanks for updating this PR. We checked the lines you've touched for [PEP 8](https://www.python.org/dev/peps/pep-0008) issues, and found:



There are currently no PEP 8 issues detected in this Pull Request. Cheers! :beers: 

##### Comment last updated at 2022-07-29 14:53:38 UTC Is the failed check expected behavior or do I need to fix something? Thanks @Mehgarg 