Source and configuration files for each manual are now located in a
separate subdirectory, with common configuration files in doc/config.
doc
|_config
|_qtcreator
|_qtcreatordev
|_qtdesignstudio
Edit the config files accordingly.
Change-Id: Idc747a7c16e84f3e06add91234dc5fc908e64cc5
Reviewed-by: Eike Ziller <eike.ziller@qt.io>
