added LSP quick diagnostic keymap

lua/keymaps.lua

@@ -26,6 +26,7 @@ mapn("<C-l>",   wincmd "l")
 mapleader("s",  vim.cmd.source)
 mapleader("w",  vim.cmd.write)
 mapleader("f",  vim.lsp.buf.format)
+mapleader("q",  vim.diagnostic.setloclist)
 mapleader("o",  function() oil.open() end)
 mapleader("O",  function() oil.toggle_float() end)
 mapleader("pf", function() pick.builtin.files() end)