fix: Make colorcolumn work properly

Setting `colorcolumn` as a window option breaks any window
that does not need it set.
Use an autocmd to fix this.

ftplugin/markdown.lua

@@ -1,3 +1,2 @@
 vim.wo.spell = true
 vim.bo.textwidth = 75
-vim.wo.colorcolumn = "75,80"

ftplugin/tex.lua

@@ -0,0 +1,2 @@
+vim.wo.spell = true
+vim.bo.textwidth = 80

ftplugin/typst.lua

@@ -1,6 +1,5 @@
 vim.wo.spell = true
 vim.bo.textwidth = 75
-vim.wo.colorcolumn = "75,80"
 
 vim.api.nvim_buf_create_user_command(0, "OpenPdf", function()
 	local filepath = vim.api.nvim_buf_get_name(0)

lua/core/autocommands.lua

@@ -1,7 +1,8 @@
 -- Control cursorline option
 -- This function allows the easy creation of autocommands that configure cursorline for one buffer
 -- either based on events or filetypes
-local auGroupCursorLine = vim.api.nvim_create_augroup("CursorLine", { clear = true })
+local auGroupCursorLine = vim.api.nvim_create_augroup("CursorLine",
+	{ clear = true })
 local set_cursorline = function(event, value, pattern)
 	vim.api.nvim_create_autocmd(event, {
 		group = auGroupCursorLine,
@@ -18,7 +19,8 @@ set_cursorline("FileType", false, "TelescopePrompt")
 -- Wrangle formatoptions
 -- Format options is local to the buffer
 -- This autocommand fixes formatoptions for all buffers at load
-local auGroupFormatOptions = vim.api.nvim_create_augroup("FormatOptions", { clear = true })
+local auGroupFormatOptions = vim.api.nvim_create_augroup("FormatOptions",
+	{ clear = true })
 vim.api.nvim_create_autocmd("FileType", {
 	group = auGroupFormatOptions,
 	pattern = "*",
@@ -28,3 +30,30 @@ vim.api.nvim_create_autocmd("FileType", {
 			- "o" -- and for newlines
 	end,
 })
+
+-- Do some magic for colorcolumn
+-- if set as a window option for a file, anything that uses that window
+-- at a later date will inherit that even if it doesn't make sense.
+local auGroupColorColumn = vim.api.nvim_create_augroup("ColorColumn",
+	{clear=true})
+vim.api.nvim_create_autocmd( 'BufEnter', {
+	group = auGroupColorColumn,
+	pattern = "*",
+	callback = function (_)
+		-- if we set textwidth we show a colorcolumn
+		if vim.bo.textwidth > 0 then
+			local warn=vim.bo.textwidth - 5
+			vim.wo.colorcolumn=string.format("%d,%d", warn, vim.bo.textwidth)
+		else
+			vim.wo.colorcolumn=""
+		end
+	end,
+	}
+)
+vim.api.nvim_create_autocmd('BufLeave',{
+	group=auGroupColorColumn,
+	pattern = '*',
+	callback = function ()
+		vim.wo.colorcolumn=""
+	end
+})