Feature Request: Add custom pinyin mapping.

[larryw3i]

Hello! Our maintainers,
I think the custom Pinyin Mapping should been added to Preferences just like my issue:
I wanna input two the full-width spaces 　　 to my document, and if I add it to the custom Pinyin Mapping and just type qjkg or zkg and ibuspinyin shows it for me, it must be convenient.

Regards,
larryw3i

[epico]

Maybe you can consider to use Lua command or Lua trigger for this purpose.