DOC: Validation errors on doctests with output too long for a single line
RE: PR #27280 

Multiple docstring tests are failing because of pretty whitespace formatting of the expected output. Here is an example from `read_json()` in `pandas/io/json/_json.py:500`
```python
Encoding/decoding a Dataframe using ``'split'`` formatted JSON:

>>> df.to_json(orient='split')
'{"columns":["col 1","col 2"],
  "index":["row 1","row 2"],
  "data":[["a","b"],["c","d"]]}'
```
Running the validation script results in the following error:
```
Line 153, in pandas.read_json
Failed example:
    df.to_json(orient='split')
Expected:
    '{"columns":["col 1","col 2"],
      "index":["row 1","row 2"],
      "data":[["a","b"],["c","d"]]}'
Got:
    '{"columns":["col 1","col 2"],"index":["row 1","row 2"],"data":[["a","b"],["c","d"]]}'
```
There is another similarly failing example in this function's doctests. `Series.to_json` has similar failures as well.

The `+NORMALIZE_WHITESPACE` directive does not help and neither do ellipses. Removing the whitespace does cure the failures, but it looks nasty. 

<details>
INSTALLED VERSIONS
------------------
commit           : c64c9cb44222a42f7b02d4d6007919cd0645f1be
python           : 3.7.3.final.0
python-bits      : 64
OS               : Darwin
OS-release       : 18.6.0
machine          : x86_64
processor        : i386
byteorder        : little
LC_ALL           : None
LANG             : en_US.UTF-8
LOCALE           : en_US.UTF-8

pandas           : 0.25.0rc0+23.gc64c9cb44
numpy            : 1.16.4
pytz             : 2019.1
dateutil         : 2.8.0
pip              : 19.1.1
setuptools       : 41.0.1
Cython           : 0.29.11
pytest           : 5.0.0
hypothesis       : 4.23.6
sphinx           : 1.8.5
blosc            : None
feather          : None
xlsxwriter       : 1.1.8
lxml.etree       : 4.3.4
html5lib         : 1.0.1
pymysql          : None
psycopg2         : None
jinja2           : 2.10.1
IPython          : 7.6.0
pandas_datareader: None
bs4              : 4.7.1
bottleneck       : 1.2.1
fastparquet      : 0.3.0
gcsfs            : None
lxml.etree       : 4.3.4
matplotlib       : 3.1.0
numexpr          : 2.6.9
odfpy            : None
openpyxl         : 2.6.2
pandas_gbq       : None
pyarrow          : 0.11.1
pytables         : None
s3fs             : 0.2.1
scipy            : 1.2.1
sqlalchemy       : 1.3.5
tables           : 3.5.2
xarray           : 0.12.1
xlrd             : 1.2.0
xlwt             : 1.3.0
xlsxwriter       : 1.1.8
</details>
