title: how to get all documents by index in Easticsearch using NEST?
body: <p>I want to GET all my documents by Index. I have tried the following:</p>
  
  <p>var response = client.Search(s => s.Index("test").MatchAll());</p>
  
  <p>the response returns "successful operation" but it hits no document despite the fact that there are many documents under that index.</p>