Add compose and attic configurations

Add compose directory to store docker/podman compose files for running
on the TrueNAS box
Add attic configurations to auto-listen on all my home boxes to upload
builds
Update nix-conf to support reading from the Attic server

compose/restic.yaml

@@ -0,0 +1,19 @@
+# Demo of rest-server with prometheus and grafana
+version: "2"
+
+services:
+  restserver:
+    image: "restic/rest-server:0.14.0"
+    volumes:
+      - /mnt/all/backups:/data
+      - /mnt/all/configs/certs:/certs
+    environment:
+      OPTIONS: >-
+        --tls
+        --tls-cert /certs/nas1.shire-zebra.ts.net.crt
+        --tls-key /certs/nas1.shire-zebra.ts.net.key
+        --path /data
+        --prometheus
+        --debug
+    ports:
+      - "30248:8000"