title: How to merge YAML arrays?
body: <p>I would like to merge arrays in YAML, and load them via ruby - </p>
  
  <pre><code>some_stuff: &amp;some_stuff
   - a
   - b
   - c
  
  combined_stuff:
    &lt;&lt;: *some_stuff
    - d
    - e
    - f
  </code></pre>
  
  <p>I'd like to have the combined array as <code>[a,b,c,d,e,f]</code></p>
  
  <p>I receive the error: did not find expected key while parsing a block mapping</p>
  
  <p>How do I merge arrays in YAML?</p>