README: reinstate combolayer readme

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>

README

@@ -1,11 +1,6 @@
-OpenEmbedded-Core
-=================
+This layer is a assembly of other layers, managed by the 'combo-layers' tool.
 
-For information about OpenEmbedded see their website:
-    http://www.openembedded.org/
-
-The Yocto Project has extensive documentation about OE including a reference manual
-which can be found at:
-    http://yoctoproject.org/community/documentation
+Pull requests need to get sent to the respective partial layer maintainers, info to follow.
 
+Main layer maintainer: Koen Kooi <koen@dominion.thruhere.net>