title: Add field to crawled content with StormCrawler (and Elasticsearch)
body: <p>I have followed the following tutorial for crawling content with stormcrawler and then store it in elasticsearch: <a href="https://www.youtube.com/watch?v=KTerugU12TY" rel="nofollow noreferrer">https://www.youtube.com/watch?v=KTerugU12TY</a> . However, I would like to add to every document the date it was crawled. Can anyone tell me how this can be done?</p>
  
  <p>In general, how can I change the fields of the crawled content?</p>
  
  <p>Thanks in advance</p>