Add mysql as an available data source into documentation (#1025)

1. Fix link
2. Add mysql into
https://evadb.readthedocs.io/en/latest/source/reference/databases/index.html
3. Add documentation requirements in
https://evadb.readthedocs.io/en/latest/source/dev-guide/extend/new-data-source.html

docs/source/dev-guide/extend/new-data-source.rst

@@ -94,5 +94,5 @@ Add the Data Source in Documentation
 
 Add your new data source into :ref:`databases` section for reference.
 
-- Create ``mydb.rst`` under `evadb/docs/source/reference/databases <https://github.com/georgia-tech-db/evadb/tree/staging/docs/source/reference/databases>`_ directory. You can refer to the existing documentation under the directory for example information to be covered in ``mydb.rst``.
-- Update ``source/reference/databases/postgres`` in `evadb/docs/_toc.yml <https://github.com/georgia-tech-db/evadb/blob/staging/docs/_toc.yml>`_.
+- Create ``mydb.rst`` under `evadb/docs/source/reference/databases <https://github.com/georgia-tech-db/evadb/tree/staging/docs/source/reference/databases>` directory. You can refer to the existing documentation under the directory for example information to be covered in ``mydb.rst``.
+- Update ``source/reference/databases/postgres`` in `evadb/docs/_toc.yml <https://github.com/georgia-tech-db/evadb/blob/staging/docs/_toc.yml>`.