add vertical rulers

lua/settings.lua

@@ -11,6 +11,7 @@ vim.opt.termguicolors = true -- enable true colors
 vim.opt.cursorline = true      -- highlight the current line
 vim.opt.wrap = false           -- do not wrap long lines
 vim.opt.signcolumn = "yes"     -- always show the sign number (LSP, git)
+vim.opt.colorcolumn = "80,100" -- vertical rulers
 
 -- Scrolling
 vim.opt.scrolloff = 8     -- keep space above/below cursor