3835: Move help to dedicated plugin

org.fortiss.af3.rcp.application/.settings/org.eclipse.core.resources.prefs

-eclipse.preferences.version=1
-encoding//html/external_tools.html=UTF-8
-encoding//model/conti.ecorediag=UTF-8
-encoding//uml/exploration.ecorediag=UTF-8
-encoding/<project>=US-ASCII