ENH: Include `df.attrs` metadata in `to_csv` output
- [ ] closes #53577
- [ ] [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.

This new functionality writes DataFrame metadata stored in df.attrs as header/comment lines at the top of a CSV file.

The `to_csv()` method had a `comment` param added to its call, matching the `read_csv()` method signature
    If this param is set all key/values will be written to the beginning of the CSV file in the following format `[comment][key]:[value]`


There was previous PR for this (#53740) that I closed. I accidentally butchered that previous branch, this is the new PR with a clean, fresh branch
This pull request is stale because it has been open for thirty days with no activity. Please [update](https://pandas.pydata.org/pandas-docs/stable/development/contributing.html#updating-your-pull-request) and respond to this comment if you're still interested in working on this. Thanks for the pull request, but it appears to have gone stale. If interested in continuing, please merge in the main branch, address any review comments and/or failing tests, and we can reopen.