How to remove extra line space on GitHub markdown bullets/lists?

Question

The GitHub markdown code:

1. First item
* subitem
1. Second item

Generates a big space between the First, Second and

Answer 1

You cannot do this going from a primary to secondary item. It is possible from a secondary to tertiary list, however. This is due to GitHub's styling of the markdown, not an inherent issue with the markdown itself.

See this document for details on what is possible regarding different layout styles.