The source project of this merge request has been removed.
tor-spec: Revise the CircID selection section
This commit updates the "5.1.1. Choosing circuit IDs in create cells" section, in order to clarify its importance, as well as to adjust it to modern link protocol versions.
The first goal is achieved, by directly adding a "MUST" in the first paragraph, alongside a reformulation in the paragraph explaining the method in link protocol version 4 or higher.
The second goal is achieved by merging the second paragraph with the third paragraph, as the second paragraph only applies to the link protocol versions addressed in the third one.