DOC: update DataFrame.to_records
Checklist for the pandas documentation sprint (ignore this if you are doing
an unrelated PR):

- [X] PR title is "DOC: update the <your-function-or-method> docstring"
- [X] The validation script passes: `scripts/validate_docstrings.py <your-function-or-method>`
- [X] The PEP8 style check passes: `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [X] The html version looks good: `python doc/make.py --single <your-function-or-method>`
- [X] It has been proofread on language by another sprint participant

Please include the output of the validation script below between the "```" ticks:

```
# paste output of "scripts/validate_docstrings.py <your-function-or-method>" here
# between the "```" (remove this comment, but keep the "```")

################################################################################
################### Docstring (pandas.DataFrame.to_records)  ###################
################################################################################

Convert DataFrame to record array.

Index will be put in the 'index' field of the record array if
requested.

Parameters
----------
index : boolean, default True
    Include index in resulting record array, stored in 'index' field.
convert_datetime64 : boolean, default True
    Whether to convert the index to datetime.datetime if it is a
    DatetimeIndex.

Returns
-------
y : recarray

See Also
--------
DataFrame.from_records: convert structured or record ndarray
    to DataFrame.
numpy.recarray: ndarray that allows field access using
    attributes, analogous to typed (typed) columns in a
    spreadsheet.

Examples
--------

>>> df = pd.DataFrame({'A': [1, 2], 'B': [0.5, 0.75]},
...                   index=['a', 'b'])
>>> df
   A  B
a     1  0.50
b     2  0.75
>>> df.to_records()
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
          dtype=[('index', 'O'), ('A', '<i8'), ('B', '<f8')])

The index can be excluded from the record array:

>>> df.to_records(index=False)
rec.array([(1, 0.5 ), (2, 0.75)],
          dtype=[('A', '<i8'), ('B', '<f8')])

By default, timestamps are converted to `datetime.datetime`:

>>> df.index = pd.date_range('2018-01-01 09:00', periods=2, freq='min')
>>> df
                     A  B
2018-01-01 09:00:00     1  0.50
2018-01-01 09:01:00     2  0.75
>>> df.to_records()
rec.array([(datetime.datetime(2018, 1, 1, 9, 0), 1, 0.5 ),
           (datetime.datetime(2018, 1, 1, 9, 1), 2, 0.75)],
          dtype=[('index', 'O'), ('A', '<i8'), ('B', '<f8')])

The timestamp conversion can be disabled so NumPy's datetime64
data type is used instead:

>>> df.to_records(convert_datetime64=False)
rec.array([('2018-01-01T09:00:00.000000000', 1, 0.5 ),
           ('2018-01-01T09:01:00.000000000', 2, 0.75)],
          dtype=[('index', '<M8[ns]'), ('A', '<i8'), ('B', '<f8')])

################################################################################
################################## Validation ##################################
################################################################################

Docstring for "pandas.DataFrame.to_records" correct. :)

```

If the validation script still gives errors, but you think there is a good reason
to deviate in this case (and there are certainly such cases), please state this
explicitly.


Checklist for other PRs (remove this part if you are doing a PR for the pandas documentation sprint):

- [ ] closes #xxxx
- [ ] tests added / passed
- [X] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry
