In Google Docs, you can now select “Automatically detect Markdown” from Tools > Preferences to enable auto correcting for Markdown syntax, a lightweight markup language for applying formatting using plain text. Currently, Google Docs supports some Markdown syntax, such as:

•  * or – followed by a space autocorrects to bullet points
• Various ways to start a numbered list similar to Markdown
• [] followed by a space autocorrects to checkboxes

The expanded support will now support autocorrection for:

1. Headings
2. Italic and bold
3. Bold + italic
4. Strikethrough
5. Links

This feature will be OFF by default and can be enabled by the user in Docs under Tools > Preferences. Visit the Help Center to learn more about turning Markdown autocorrection on or off for your account. 

Extended rollout (potentially longer than 15 days for feature visibility) started on March 29, 2022.

See this Google page for details.