title: Increment arg in jq
body: <p>I have something like: </p>
  
  <pre><code>jq --arg START 10 '[.z[] | select(has("name")) | {id: $START | tonumber, name}]'
  </code></pre>
  
  <p>transforming to an array of objects with a 'name' key, appending an incremental id, which outputs:</p>
  
  <pre><code>[
    {
      id: 10,
      name: "stuff"
    },
    {
      id: 10,
      name: "more stuff"
    }
  ]
  </code></pre>
  
  <p>How can I increment the START arg so that the second object has an id of 11 and so on?</p>
  
  <p>EDIT: I should have posted the original json:</p>
  
  <pre><code>{
    "u": "stuff",
    "x": [1,2,3],
    "y": {
      "field": "value"
    },
    "z": {
      "stuffWithoutName": {
         "ex": "stuff"
      },
      "zz": {
         "name": "change me",
         "more": "stuff"
      },
      "randomKey":  {
         "name": "change me",
         "random": "more stuff"
      }
    }
  }
  </code></pre>
  
  <p>Thanks!</p>