Add example recipes to build a single image

Sample recipes with new recipe action

Fixes: APERTIS-5675

overlays/ostree/usr/share/initramfs-tools/hooks/rootfsck

+#!/bin/sh
+
+# Copy utilities for root filesystem check in initramfs
+
+PREREQ=""
+
+prereqs()
+{
+        echo "$PREREQ"
+}
+
+case $1 in
+prereqs)
+        prereqs
+        exit 0
+        ;;
+esac
+
+. /usr/share/initramfs-tools/hook-functions
+
+copy_exec /sbin/fsck
+copy_exec /sbin/logsave
+copy_exec /sbin/fsck.ext4