[minimal] remove base group, [kde] set XRender as banckend.

editions/minimal

 ## Maintained by Strit ##
 
 # Minimal packages
-base
 sudo
 archlinuxarm-keyring
 parted

overlays/kde/etc/skel/.config/kwinrc

 [Compositing]
+AnimationSpeed=0
+Backend=XRender
 OpenGLIsUnsafe=false
+Enabled=true
+GLCore=false
+WindowBlockCompositing=true
+XRenderSmoothScale=false
 
 [Desktops]
 Number=1