Remove reference to a `room_id` key for typing events (#1265)

changelogs/client_server/newsfragments/1265.clarification

@@ -0,0 +1 @@
+Fix various typos throughout the specification.

content/client-server-api/modules/typing_notifications.md

@@ -6,8 +6,9 @@ type: module
 
 Users may wish to be informed when another user is typing in a room.
 This can be achieved using typing notifications. These are ephemeral
-events scoped to a `room_id`. This means they do not form part of the
-[Event Graph](index.html#event-graphs) but still have a `room_id` key.
+events, so they do not form part of the
+[Event Graph](index.html#event-graphs). Typing notifications are scoped
+to a room.
 
 #### Events