You could try Visual Studio Code, which apparently supports Markdown.

I tend to edit Markdown files in Emacs though.

If a reply is not forthcoming here, be sure to ask on the Windows 10 for Screen Reader Users group.

• Post: win10@win10.groups.io
• Subscribe: win10+subscribe@win10.groups.io
• Unsubscribe: win10+unsubscribe@win10.groups.io
• Group Owner: win10+owner@win10.groups.io
• Help: win10+help@win10.groups.io

I know that several regulars there use Markdown, and with various screen readers, so someone's got to have a suggestion.
--

Brian - Windows 10 Pro, 64-Bit, Version 1809, Build 17763  

Here is a test to find out whether your mission in life is complete.  If you’re alive, it isn’t.

       ~ Lauren Bacall