Add Old Hangul to Korean IME

Hello, it would be nice if we had a Korean IME for Old Hangul (옛한글). Many scripts have already been developed (such as akorn-input, you can try live version here.)

[Dausithereru]

Yes, add SIL Romaja too. Its the easiest korean keyboard layout. no need to learn romanization.
https://en.wikipedia.org/wiki/Keyboard_layout#Korean