title: Add several subdocument in mongodb
body: <p>i have the following strucure:</p>
  
  <pre><code>{
  'name':'something',
  'commens':{
              'value':'something'
             }, {
              'value':'something else'
             }
  }
  </code></pre>
  
  <p>My question is, how can i insert/update those subdocuments?</p>