Added icons in sign column

after/plugin/lsp.lua

@@ -30,9 +30,15 @@ lsp.configure('lua_ls', {
     },
 })
 
-lsp.on_attach(function(client, bufnr)
+lsp.on_attach(function(_, bufnr)
   lsp.default_keymaps({buffer = bufnr})
 end)
 
+lsp.set_sign_icons({
+  error = '✘',
+  warn = '▲',
+  hint = '⚑',
+  info = '»'
+})
 
 lsp.setup()