ENH: col descriptions that'd save in df schemas, helping users avoid creating separate documentation?
[Asked at SO](https://stackoverflow.com/questions/68403642/saving-pandas-dataframes-in-formats-including-data-descriptions-or-other-self-do/): I need to share well described data and want to do this in a modern way that avoids managing bureaucratic documentation no one will read. Fields require some description or note (eg. "values don't include ABC because XYZ") which I'd like to associate to columns that'll be saved with `pd.to_<whatever>()`.

[Looks like JSON supports annotations](http://json-schema.org/understanding-json-schema/reference/generic.html#annotations) and I'd love to have the option of using them with pandas, but [couldn't figure out how to](https://stackoverflow.com/questions/68403642/saving-pandas-dataframes-in-formats-including-data-descriptions-or-other-self-do/). 

Could we please develop functionality to add descriptions in a convenient way (eg. `df[col].description = 'string'`) and have that save in output schemas? And maybe have that be selectable and show with `df.info(verbose=True)` or similar?

I know documentation is boring but maintaining bureaucratic paperwork is even worse. Also, data documentation is a requirement common to big orgs and schools / unis, and I reckon providing innovative functionality to make boring tasks more enjoyable is an efficient way of getting more people to ~~stop using excel~~ use pandas and newer technology in general, making the world a better place.

Unfortunately I don't understand pandas enough to see how this might be a stupid idea. Is this possible?