kuma: monitor the 7 booking instances + penpot [#685]

These 8 apps were the postgres connection hogs - invisible to monitoring
until now. Detail: https://projects.knownelement.com/issues/685

oam/kuma/cloudron-apps.txt

@@ -1,11 +1,18 @@
 ap4ap.org
 bi.knownelement.com
+booking.rackrental.net
+booking.reachableceo.com
+booking.roguetechnologies.net
+booking.startinglineproductions.com
+booking.teamrental.net
+booking.thepeernet.com
 bookmarks.knownelement.com
 broadcast.thepeernet.com
 broadcast.turnsys.com
 building-management.knownelement.com
 chat.knownelement.com
 community.turnsys.com
+design.knownelement.com
 erp.knownelement.com
 esign.knownelement.com
 ezeda.org