Linux: Fix pipe character on ASUS laptops

Is your pipe/backslash key not typing pipes and backslashes? Is it typing less-than and greater-than symbols? If so, add...

key <LSGT> { [ backslash, bar, backslash, bar] }; /usr/share/X11/xkb/symbols/us in the kxb_symbols "basic" section.

This seems to be a problem with ASUS laptops, I've seen two of them doing this.