DOC: Link to table schema and remove reference to internal API
- [x] closes #33130
- [ ] tests added / passed (Not needed)
- [x] passes `black pandas`
- [ ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff` (Markdown link which will not be shown)
- [ ] whatsnew entry (Not needed)

Hello @Bharat123rox! Thanks for updating this PR. We checked the lines you've touched for [PEP 8](https://www.python.org/dev/peps/pep-0008) issues, and found:



There are currently no PEP 8 issues detected in this Pull Request. Cheers! :beers: 

##### Comment last updated at 2020-04-26 18:02:03 UTC > Hello @Bharat123rox! Thanks for opening this PR. We checked the lines you've touched for [PEP 8](https://www.python.org/dev/peps/pep-0008) issues, and found:
> 
> * In the file [`pandas/io/json/_table_schema.py`](https://github.com/pandas-dev/pandas/blob/ee053e84117c72f9b5da489992f1f5500bb47eba/pandas/io/json/_table_schema.py):
> 
> > [Line 214:89](https://github.com/pandas-dev/pandas/blob/ee053e84117c72f9b5da489992f1f5500bb47eba/pandas/io/json/_table_schema.py#L214): [E501](https://duckduckgo.com/?q=pep8%20E501) line too long (110 > 88 characters)

This is because of Markdown Link Text, the line will not be longer in the original documentation, so this should be okay > > Hello @Bharat123rox! Thanks for opening this PR. We checked the lines you've touched for [PEP 8](https://www.python.org/dev/peps/pep-0008) issues, and found:
> > 
> > * In the file [`pandas/io/json/_table_schema.py`](https://github.com/pandas-dev/pandas/blob/ee053e84117c72f9b5da489992f1f5500bb47eba/pandas/io/json/_table_schema.py):
> > 
> > > [Line 214:89](https://github.com/pandas-dev/pandas/blob/ee053e84117c72f9b5da489992f1f5500bb47eba/pandas/io/json/_table_schema.py#L214): [E501](https://duckduckgo.com/?q=pep8%20E501) line too long (110 > 88 characters)
> 
> This is because of Markdown Link Text, the line will not be longer in the original documentation, so this should be okay

Thanks for the PR. This will need to be fixed - we run flake8 in our code checks. > Thanks for the PR. This will need to be fixed - we run flake8 in our code checks.

@alimcmaster1 I believe that the long URL is readable (self-explanatory?) and should not be broken (also while rendering it won't be shown), hence it's a strong enough case to ignore the flake8 warning > Doc build seems to be failing - mind taking a look?

Found this warning
```
/home/runner/miniconda3/envs/pandas-dev/lib/python3.8/site-packages/IPython/sphinxext/ipython_directive.py:1023: UserWarning: Code input with no code at /home/runner/work/pandas/pandas/doc/source/user_guide/computation.rst, line 624
  warnings.warn(message)
/home/runner/work/pandas/pandas/pandas/io/json/_table_schema.py:docstring of pandas.io.json.build_table_schema:45: WARNING: Explicit markup ends without a blank line; unexpected unindent.
```
But I didn't even touch line 45, so what is this really about? did you build this page locally and see if it renders and the link works? > did you build this page locally and see if it renders and the link works?

@jreback I'm still having problems building docs locally in MacOS, but I did try it on an RST Previewer and it works fine thanks @Bharat123rox 