title: add values to array of keys with JQ
body: <p>I have a simple JSON array:</p>
  
  <pre><code>[
  "smoke-tests",
  "other-tests"
  ]
  </code></pre>
  
  <p>I'd like to convert to a simple JSON:</p>
  
  <pre><code>{"smoke-tests": true,
   "other-tests": true
  }
  </code></pre>
  
  <p>I've tried several jq examples, but none seem to do what I want.</p>
  
  <p><code>jq '.[] | walk(.key = true)'</code> produces a compile error.</p>