Fix grammar in room tag spec
Have removed the second clause about how the client interprets them:
I was trying to think how to rephrase it but I think in reality it's
probably just redundant.
@@ -41,7 +41,7 @@ after the rooms with that tag that have an ``order`` key.
The name of a tag MUST not exceed 255 bytes.
-Tags namespaces are defined in the following way, depending on how the client are expected to interpret them:
+The tag namespace is defined as follows:
* The namespace ``m.*`` is reserved for tags defined in the Matrix specification. Clients must ignore
any tags in this namespace they don't understand.
