title: Filter JavaScript object by key's prefix and reduce to build new objects
body: <p>I'm pulling from a large data dump API and need to filter the data better. Currently, this is an example of what I am seeing.</p>
  
  <pre><code>{
    AA-Short: "information",
    AA-Long: "more information",
    AA-Extra: "even more information",
    BB-Short: "information",
    BB-Long: "more information",
    BB-Extra: "even more information",
  } 
  </code></pre>
  
  <p>I'm trying to make this:</p>
  
  <pre><code>{
    AA: {
       AA-Short: "information",
       AA-Long: "more information",
       AA-Extra: "even more information"
    },
    BB: {
       BB-Short: "information",
       BB-Long: "more information",
       BB-Extra: "even more information"
    }
  } 
  </code></pre>