Appoint Martin Chacon Piza as Monasca PTL

Martin Chacon Piza  sent their late candidacy
for Monasca PTL position of Xena Cycle
- https://review.opendev.org/c/openstack/election/+/779632

Change-Id: I2659940850083e4510c6780e4c39e725b8b6fbae

reference/projects.yaml

@@ -941,9 +941,11 @@ mistral:
       - diablo_rojo
 monasca:
   ptl:
-    name: APPOINTMENT NEEDED
-    irc: No nick supplied
-    email: example@example.org
+    name: Martin Chacon Piza
+    irc: chaconpiza
+    email: martin@chaconpiza.com
+  appointed:
+    - xena
   irc-channel: openstack-monasca
   service: Monitoring
   mission: >