If Android Studio is not showing previews for markdown files, do the following:

1. Go to menu Help -> Find Action(Ctrl+Shift+A) -> Choose Boot Time Java for the IDE -> and select JetBrains Runtime with JCEF

2. Restart the IDE:

3. Now the preview should be working:

 I am starting to open source my old Android games.

The first one to bite the dust is : Crate Jump