[Global Addressing] Requirements section requires introductory paragraph, and potential reordering

Currently the requirements section is a bullet list with no context. I think an introductory scene-setting paragraph is required.

Secondly I think the requirements are in a somewhat odd order... I would consider that the first requirement would be better being "Defining the relationship between to and source/target" one i.e. linking back to the AMQP spec which is obviously incomplete... the other requirements are then extending this to cover scopes we think are important.

Thirdly the "AMQP address may optionally advertise" part seems odd. The addresses themselves don't advertise, it would be closer to say the support advertisement or something like that.