Describe the bug

Docs section https://mendeleev.readthedocs.io/en/latest/data_access.html#export-data not rendering the code block properly.

To Reproduce

Steps to reproduce the behavior:

1. Import '...'

Expected behavior

A clear and concise description of what you expected to happen.

Screenshot

If applicable, add screenshots to help explain your problem.

Specification

• mendleev version
• python version
• platform

Additional context

Add any other context about the problem here.