Add "description" to list of fields that MAY be included in stream creation

[FragLegs]

In section 7.1.1.1, we say that the stream creation request MAY include any Receiver-supplied fields, and then we list events_requested and delivery. We should either include description as well, or remove the list and let implementers discover which fields are Receiver-supplied above in section 7.1.1 (the latter option being more future-proof if we add any other Receiver-supplied fields in later versions).

[tulshi]

Seems reasonable. You haven't marked this for v3, so would you like this to be addressed right now, or after v3?

[FragLegs]

It's not essential. We can wait until after v3, since it is just a clarity edit.