title: silver_searcher (ag) with multiple search expressions?
body: <p>Does <a href="https://github.com/ggreer/the_silver_searcher" rel="noreferrer">silver_searcher</a> support specifying multiple search expressions something like <code>-e</code> in <code>grep</code>?</p>
  
  <p>I could not find any option in the document/help. </p>