title: mongoDB prefix wildcard: fulltext-search ($text) find part with search-string
body: <p>I have mongodb with a <code>$text-Index</code> and elements like this:</p>
  
  <pre><code>{
     foo: "my super cool item"
  }
  {
     foo: "your not so cool item"
  }
  </code></pre>
  
  <p>If i do search with </p>
  
  <pre><code>mycoll.find({ $text: { $search: "super"} })
  </code></pre>
  
  <p>i get the first item (correct).</p>
  
  <p>But i also want to search with "uper" to get the fist item - but if i try:</p>
  
  <pre><code>mycoll.find({ $text: { $search: "uper"} })
  </code></pre>
  
  <p>I dont get any results.</p>
  
  <p>My Question:
  If there is a way to use $text so its finds results with a part of the searching string? (e.g. like <code>'%uper%'</code> in <code>mysql</code>)</p>
  
  <p><strong>Attention: I dont ask for a regex only search - i ask for a regex-search within a $text-search!</strong></p>