Add extra paragraph to services/bobachat describing federation

content/services/bobachat.md

@@ -20,6 +20,11 @@ https://app.element.io). Make sure that the field labeled `Host
 account on` says `boba.best`. This is set by default on
 https://element.boba.best, but it won't be on other clients.
 
+Note that you aren't limited to talking to just people on the bobachat
+homeserver. You can join any room, regardless of homeserver (rooms are
+duplicated between all the homeservers participating in them). People on other
+Matrix homeservers can also talk to you.
+
 ## bobaspace
 
 Spaces are a way to group rooms together easily. The official bobachat space