STYLE improve `validate-docstrings` ergonomics
Before opening an issue for EX03 errors, I just wanted to improve the usability of `validate_docstrings`

Currently it's kind of hard to tell which lines need to change, especially if there's a long docstring.

Now, here's what it shows for `python scripts/validate_docstrings.py pandas.Series.describe`:
```python
################################################################################
################################## Validation ##################################
################################################################################

3 Errors found for `pandas.Series.describe`:
        flake8 error: line 11, col 54: E231 missing whitespace after ','
        flake8 error: line 11, col 58: E231 missing whitespace after ','
        flake8 error: line 14, col 19: E124 closing bracket does not match visual indentation
```

From trying it out locally, this makes it much easier to tell what needs changing
Thanks @MarcoGorelli  Arrived late to the party