title: Get first element of nested array for hash key
body: <p>Supposing I have an array that looks like:</p>
  
  <pre><code>[
    [["str1"],["val1"],["val2"]],
    [["str2"], ["val1"], ["val2"], ["val3"]]
  ] 
  </code></pre>
  
  <p>Is there a way for me to get a Hash that looks like:</p>
  
  <pre><code>{
    "str1" =&gt; [["val1"],["val2"]],
    "str2" =&gt; [["val1"],["val2"],["val3"]]
  }
  </code></pre>