report unicode.org file change

[justinmk]

neovim/neovim#2159 (comment)

if any of the unicode.org files change, we need a reminder to run scripts/genunicodetables.lua.

[fwalch]

Or we can do it like neovim/bot-ci#52 and let Marvim create a pull request :-)

[justinmk]

Indeed :)