title: multiple queries on multiple indices and different rules in elastalert
body: <p>I want to run multiple queries on multiple indices of elasticsearch in elastalert. How can I do that?
  for example : I want to use the first filter and type "any" on index abc*, the second filter and type "frequency" on index xyz*</p>
  
  <pre><code> type: any
   type: frequency
   index: abc*
   index: xyz*
   filter:
    - match:
      loglevel: "INFO"
   filter:
    - match:
      loglevel: "ERROR"
  </code></pre>