title: JQ how to join array in one line?
body: <p>I have json file:</p>
  
  <pre><code> [ 
   {
   "query": {
   "key1": "value1",
   "key2": "value2"
   }
   }
   ]
  </code></pre>
  
  <p>Need to join this array with one line so output will be:</p>
  
  <pre><code>key1=value1&amp;key2=value2
  </code></pre>
  
  <p>I can join it values:</p>
  
  <pre><code>jq '.[].query | join("&amp;")'
  "value1&amp;value2"
  </code></pre>
  
  <p>Or </p>
  
  <p>Get key value string:</p>
  
  <pre><code>jq '.[].query | to_entries[] | "\(.key)=\(.value)"'
  "key1=value1"
  "key2=value2"
  </code></pre>
  
  <p>But how to concatenate this?
  Regards</p>