Feature suggestion: enhance SE Markdown for em-dash

Question

I would love if the Stack Exchange implementation of Markdown converted the character sequence

-- (two minus signs or dashes, when not part of a larger sequence of dashes)

to

— (—).

The way text looks--with two dashes--is just so much less polished than when you use a proper em-dash.

Contrast with:

The way text looks—with two dashes—is just so much less polished than when you use a proper em-dash.