Synopsis:
   bind <key> bold

Description:
   This function toggles the current boldface setting.  Due to internal
   limitations of the client, BOLD is displayed as a B on the input line,
   regardless of the key it is bound to.

See Also:
   bind(4) blink, highlight_off, reverse, underline;
   set(4) bold_video

Other Notes:
   Boldfaced text can be typed at any time, but it will only be displayed
   if BOLD_VIDEO is on.