If you need to install layman, please follow these tips.
Our overlay it's in the layman global list. If for some reason it doesn't work, try following the alternative instructions
You may want to run:
layman --fetch
just to be sure your list is up to date. Then add pd-overlay:
layman --add pd-overlay
layman --sync=pd-overlay
or simply run:
layman -S
and it will get synced among with other overlays.