Enhance Telescope command (#588)

* Enhance Telescope command close #581

* bug fix

lua/telescope/command.lua

@@ -131,6 +131,11 @@ end
 
 function command.load_command(cmd,...)
   local args = {...}
+  if cmd == nil then
+    run_command({cmd = 'builtin'})
+    return
+  end
+
   local user_opts = {}
   user_opts['cmd'] = cmd
   user_opts.opts = {}

plugin/telescope.vim

@@ -100,4 +100,4 @@ function! s:telescope_complete(arg,line,pos)
 endfunction
 
 " Telescope Commands with complete
-command! -nargs=+ -complete=custom,s:telescope_complete Telescope    lua require('telescope.command').load_command(<f-args>)
+command! -nargs=* -complete=custom,s:telescope_complete Telescope    lua require('telescope.command').load_command(<f-args>)