title: Add element to an array in a dictionary in TCL
body: <p>I'm triny to add an element to an array (list?) in a dictionary and can't wrap my head around the problem.</p>
  
  <p>I'm creating a dict from json object, that looks roughly like this:</p>
  
  <pre><code>{"channel1":{"badwords":["test", "demo"]}, "channel2":{"badwords":["remove"]}}
  </code></pre>
  
  <p>This JSON is transformed into a dict, and I can access badwords as</p>
  
  <pre><code>[dict get $channels "channel1" "badwords"]
  </code></pre>
  
  <p>I need to update the dict by adding a new value to it, basically make it a:</p>
  
  <pre><code>{"channel1":{"badwords":["test", "demo", "new"]}, "channel2":{"badwords":["remove"]}}
  </code></pre>