Include "CN" column number symbol

[scolby33]

Some Powerline fonts have a stacked "CN" symbol at U+E0A3 like the "LN" symbol.

For example:

• https://github.com/vim-airline/vim-airline/blob/master/doc/airline.txt#L381
• https://github.com/ryanoasis/powerline-extra-symbols/blob/master/img/fontforge.png

Could this be added to Fira Code?

[tonsky]

Yes, thank you