feat: add initial Nexus3 files

nexus3/probes/readiness.sh

@@ -0,0 +1,13 @@
+#!/bin/sh
+
+curl -siu admin:admin123 http://localhost:8081/service/metrics/ping | grep pong
+RESPONSE=$?
+
+if [ "$RESPONSE" = "0" ] ; then
+  echo "******** readiness is Alive ********"
+  exit 0;
+else
+  echo "******** readiness is Dead ********"
+  exit 1;
+fi
+