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 the subitem:

How to make the subitem close to the first item, instead of exactly on the middle of them?

This is a Photoshop I did to illustrate the correct output:

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Related questions:

1. Multi paragraph list items, OR preventing numbered list auto formatting
2. Markdown: Problems with numbered list paragraphs containing code element

Solution 1

You need to indent the sublist with at least 4 spaces:

1. First item
    * subitem
2. Second item

Solution 2

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.