Add routing mode count to phone home docs [CORE-127] (#1120)

docs/modules/ROOT/pages/phone-homes.adoc

@@ -21,6 +21,7 @@ The following information is sent in a phone home:
 * Number of active client connections during the phone home ping; bands of 5, 10, 20, 40, 60, 100, 150, 300, 600 and > 600
 * Number of clients connected since the last phone home ping
 * Number of clients disconnected since the last phone home ping
+* Number of active client connections with routing mode SMART, UNISOCKET and SUBSET
 * Total duration of client connections since the last phone home ping
 * Versions of the connected, disconnected or active clients since the last phone home ping
 * Cluster uptime