message: Add "CSRF" challenge description and hint to i18n strings
diff: " <em>(This challenge is <strong>potentially harmful</strong> on Heroku!)</em>": " <em>(This challenge is <strong>potentially harmful</strong> on Heroku!)</em>",
  "Find the endpoint that serves usage data to be scraped by a <a href=\"https://github.com/prometheus/prometheus\">popular monitoring system</a>.": "Find the endpoint that serves usage data to be scraped by a <a href=\"https://github.com/prometheus/prometheus\">popular monitoring system</a>.",
  "Try to guess what URL the endpoint might have.": "Try to guess what URL the endpoint might have.",
  - "Look for a url parameter where its value appears in the page it is leading to.": "Look for a url parameter where its value appears in the page it is leading to."
  + "Look for a url parameter where its value appears in the page it is leading to.": "Look for a url parameter where its value appears in the page it is leading to.",
  + "Change the name of a user by performing Cross-Site Request Forgery from <a href=\"http://htmledit.squarefree.com\">another origin</a>.": "Change the name of a user by performing Cross-Site Request Forgery from <a href=\"http://htmledit.squarefree.com\">another origin</a>.",
  + "Find a form which updates the username and then construct a malicious page in the online HTML editor.": "Find a form which updates the username and then construct a malicious page in the online HTML editor."
  }
  \ No newline at end of file
  