title: Storing only selected fields and not storing _all in pyes/elasticsearch
body: <p>I am trying to use pyes with elasticsearch as full text search engine, I store only UUIDs and indexes of string fields, actual data is stored in MonogDB and retrieved using UUIDs. Unfortunately, I am unable to create a mapping that wouldn't store original data, I've tried various combinations of "store"/"source" fields and disabling "_all" but I can still get text of indexed fields. It seems that documentation is misleading on this topic as it's just a copy of original docs.</p>
  
  <p>Can anyone please provide an example of mapping that would only store some fields and not the original document JSON?</p>