title: swift add element in a array of dictionary nested in a dictionary
body: <p>I have the following code :</p>
  
  <pre><code>var TabActions: Dictionary&lt;String, Array&lt;Dictionary&lt;String, String&gt;&gt;&gt; = [:]
  
  TabActions = ["EVENT1" : ["TARGET1" : "ACTION1"], ["TARGET2" : "ACTION2"]]
  </code></pre>
  
  <p>I want to add ["TARGET3" : "ACTION3"] to the list but I can't figure how to do this. I've tried :</p>
  
  <pre><code>TabActions["EVENT1"] = [["TARGET3" : "ACTION3"]]
  </code></pre>
  
  <p>but it replaces the value instead of adding it and all other attempts end up with an error</p>
  
  <p>What would be the best syntax to do this ?</p>