[Nutch Wiki] Update of "FAQ" by DanielLopez

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- After that, you should be able to retrieve the mime-type and content-length 
through the class HitDetails (via the fields "primaryType", "subType" and 
"contentLength") as you normally do for the title and URL of the hits.
+ After that, '''don't forget to crawl again''' and you should be able to 
retrieve the mime-type and content-length through the class HitDetails (via the 
fields "primaryType", "subType" and "contentLength") as you normally do for the 
title and URL of the hits.
        (Note by DanielLopez) Thanks to Doğacan Güney for the tip.
  
  === Crawling ===