Hardcoding a charset causes trouble when porting Vim patches.
I previously tried to unset "charset" for certain file extensions, but
vim-patch.sh can generate more files, and automatically detecting file
encoding is more correct anyway.
We established a while ago that 100 chars is our line length for both C
and Lua. Not all editorconfig plugins support the "max_line_length"
option, but many do (including all of the ones available for Vim/Neovim
to the best of my knowledge).
