### Summary

It would be helpful if the generic `Unknown DOCUMENTATION error` indicated which of the documentation blocks was being parsed the the time the exception was hit.

### Issue Type

Feature Idea

### Component Name

ansible-test

### Additional Information

Locally I run `ansible-test sanity --docker default -vv` using the devel branch to try and keep ahead of new sanity tests (I know this is expected to break from time to time, and I'm good with that).

I hit the following error:
```
ERROR: plugins/modules/ec2_snapshot_info.py:0:0: documentation-error: Unknown DOCUMENTATION error, see TRACE: while scanning a simple key
  in "<unicode string>", line 72, column 13
could not find expected ':'
  in "<unicode string>", line 73, column 13
```

Because I hadn't changed this module it took me some time to figure out where the failure was occurring, being able to narrow down which of the documentation blocks had some bad YAML would have saved me time.  This is especially the case for these documentation tests because the line numbers aren't easy to trace.

### Code of Conduct

- [X] I agree to follow the Ansible Code of Conduct
from __future__ import (absolute_import, division, print_function)
__metaclass__ = type
import ast
import os
import pyclbr
import tokenize
from ansible import constants as C
from ansible.errors import AnsibleError
from ansible.module_utils._text import to_text, to_native
from ansible.parsing.yaml.loader import AnsibleLoader
from ansible.utils.display import Display
display = Display()
string_to_vars = {
    'DOCUMENTATION': 'doc',
    'EXAMPLES': 'plainexamples',
    'RETURN': 'returndocs',
    'ANSIBLE_METADATA': 'metadata',  
}
def _init_doc_dict():
    ''' initialize a return dict for docs with the expected structure '''
    return {k: None for k in string_to_vars.values()}
def read_docstring_from_yaml_file(filename, verbose=True, ignore_errors=True):