I have always believed that instead of **bold** and *italic*, it should be *bold* and _italic_.
That extra asterisk is a poor design decision in markdown. It really makes it inconvenient to edit Markdown on a phone or tablet.
I’m sure back in the old days of READMEs, long before markdown was a thing, the conventions were this:
/italics/
_underline_
*bold*According to my own local Markdown formatters, the answer would be both "usr" and "bin", with the surrounding slashes removed, but the internal slash remaining. In other words:
usr/bin
(but underlined instead of italic!)
Of course, this problem is nothing new since a filename might easily be named `_my_file_`.
But also, this convention predated rendering text/plain as text/html
I don't know how well RFC 1855 reflected common practice, though. It might be worthwhile to check the rendering code in clients like tin and mutt.