Then make the form that the user enters data into be either parsed differently, by pre-processing it, or have some javascript magic that automatically adds the

Then make the form that the user enters data into be either parsed differently, by pre-processing it, or have some javascript magic that automatically adds the extra two spaces required to make it work. This way if the user presses <Enter><Enter> then the JS can remove the extra two spaces and it will still be valid markdown.