Markdown is great and I build another app, FoldingText, around it.
But for my own use I over time realized that was a mistake. All the parsing and formatting adds complexity. I think rich text (which to be clear Bike does not yet have, though I will add soon) is a simpler way to work from user perspective. Just issue commands instead of remember and see formatting rules. It's cleaner and simpler for my uses.
For example, Dynalist use this idea for their files
And node itself is heading, while when they need paragraph with heading they create _note="" attribute into <outline> element