nvim: autocmd: Open quickfix & localist list if populated

This is required when using vimgrep without which we will
have to invoke copen or lopen manually.

nvim/.config/nvim/lua/autocmd.lua

@@ -42,6 +42,18 @@ local aucmd_dict = {
       pattern = "*",
       command = "set guicursor=a:hor1-blinkon0"
     }
+  },
+  QuickFixCmdPost = {
+    {
+      group   = custom_augroup_id,
+      pattern = "[^l]*",
+      command = "cwindow"
+    },
+    {
+      group   = custom_augroup_id,
+      pattern = "l*",
+      command = "lwindow"
+    }
   }
 }