Use [shift] + [-] to input "破折號" as default

1. Set "—" (em dash) as default for [shift] + [-], in order to input "破折號" easier.
2. Add "―" (horizontal bar/quotation dash) and "﹋" (wavy overline)
3. Remove the followeing symbols to avoid misuse:
  - "ˍ" (MODIFIER LETTER LOW MACRON)
  - "╴" (BOX DRAWINGS LIGHT LEFT)
  - "﹣" (SMALL HYPHEN-MINUS)
4. Tune the order of candidates