Add support for Composition Symbol U+2384

[arrufat]

Hi, thank you so much for working on this font, I enjoy using it on Linux.
I make heavy use of the compose key feature to type non-basic Latin characters (such as my name).
It would be great if Plex supported this composition symbol U+2384 (⎄)
Right now, I just see tofu when I use it. It's surprising how few fonts support it.

Thanks in advance.