Fix lowered submenu indicators.
Apparently, floating content in a
white-space: nowrap parent will end up on
a line after any previous content in the same parent in firefox 60, but not
firefox 63. Fix this by putting the floating content first; it occupies no
space in its parent anyway, so any other content should be unaffected.
Tested on firefox 60, 63, and chromium 70
Closes: #58 (closed)