Remove notice about wiki content migration

docs/index.md

 # CiviCRM Developer Guide
 
-!!! warning "Notice"
-    This guide is not yet complete.
-    As of early 2017 we are actively working to migrate content in from the
-    [wiki]. Read more about this [migration process][migration], including how
-    to help out!
-
-[wiki]: http://wiki.civicrm.org/confluence/display/CRMDOC/Develop
-[migration]: https://wiki.civicrm.org/confluence/display/CRMDOC/Content+migration+from+wiki+to+Developer+Guide
-
-
 [CiviCRM](https://civicrm.org) is an open-source application. The code can be
 poked, prodded, twisted, and hacked. It can be customized, extended, and
 collaboratively developed. This documentation tells you how to do that.