Single emphasis on comments is not consistent with double emphasis

[goodhoko]

Describe the bug
Wrapping a <!-- --> comment in single _ or * emphasis is not consistent with wrapping a comment in double __ or ** emphasis.

To Reproduce

md	html
_<!-- foo -->_	_<!-- foo -->_
*<!-- foo -->*	*<!-- foo -->*
__<!-- foo -->__	<strong><!-- foo --></strong>
**<!-- foo -->**	<strong><!-- foo --></strong>

1. Marked Demo
2. CommonMark Demo (they actually got it right)

Expected behavior

md	html
_<!-- foo -->_	<em><!-- foo --></em>
*<!-- foo -->*	<em><!-- foo --></em>
__<!-- foo -->__	<strong><!-- foo --></strong>
**<!-- foo -->**	<strong><!-- foo --></strong>

[calculuschild]

I believe this is fixed by #1686

[UziTech]

Should be fixed with marked v1.1.1 🎉

[goodhoko]

@UziTech I can confirm. Thanks a lot! 👍 🖤