How to make auto section numbering like the documentation page of myst-parser

[zxtxin]

For example, in
https://myst-parser.readthedocs.io/en/latest/syntax/syntax.html
this page.
The sub title is auto numbering, but the main title is excluded.
How can I make it?

[chrisjsewell]

Yeh so I "cheated" there, and used some custom CSS 😅 https://github.com/executablebooks/MyST-Parser/blob/75ef9cb7b65c98d969724fc6c096e8d6209c5ea0/docs/_static/custom.css#L1