We are expanding support of lightweight formatting to include additional Markdown syntax features. This includes strikethrough formatting and nested lists. To get started, explore these new options in the formatting toolbar, keyboard shortcuts, or by editing the Markdown syntax directly.
Source: Microsoft.
I wish TextEdit supported markdown 🥹
It’s strange because Notes.app currently supports it. I’d be more likely to use it in TextEdit. Don’t really need or want it in the notes app.