DOC: Improve error message when the docstring sections are in the wrong order
When checking for errors with `scripts/validate_docstrings.py`, one of the checks is to make sure that the sections are in the right order. But so far we didn't find a great way to report the error, so the user quickly knows what needs to be changed (see discussion in https://github.com/pandas-dev/pandas/pull/23607#discussion_r232697901).

For example, if the sections in the docstring are:
```
See Also
Returns
Examples
```

The reported error is:
```
pandas.Series.infer_objects: Wrong order of sections. "Returns" should be located before "Yields", the right order is: Parameters > Attributes > Methods > Returns > Yields > Other Parameters > Raises > Warns > See Also > Notes > References > Examples
```

A better option is probably to simply return the sections in the docstring in the right order:
```
pandas.Series.infer_objects: Sections are in the wrong order. Correct order is: Returns, See Also, Examples
```

CC: @TomAugspurger 