VIM: colour column on textwidth or if not set col 80

This had to be done in a FileType * autocmd so that it is done once file
type has been determined and textwidth is set, as suggested by tae on
discord

https://discordapp.com/channels/732504251980578826/735225561240174693/763021897377775616

nvim/.config/nvim/autoload/mine/functions.vim

@@ -10,3 +10,11 @@ function! mine#functions#text() abort
 	inoremap <buffer> ; ;<C-g>u
 	inoremap <buffer> ? ?<C-g>u
 endfunction
+
+function! mine#functions#colorcols() abort
+	if &textwidth > 0
+		setlocal colorcolumn=+0
+	else
+		setlocal colorcolumn=80,100
+	endif
+endfunction

nvim/.config/nvim/plugin/settings.vim

@@ -43,3 +43,8 @@ let g:netrw_browsex_viewer = "opout"
 set formatoptions+=r
 " Automatically insert comment leader after hitting o or O
 set formatoptions+=o
+
+augroup colorcols
+	autocmd!
+	autocmd FileType,VimEnter,BufEnter * call mine#functions#colorcols()
+augroup end