2021: Update for reserved syntax (RFC 3101) #1069
Description
The tokens chapter needs to be updated for the new edition behavior. See RFC 3101 and the edition guide chapter for more.
Note that the lexical chapters are in sore need of a major overhaul (see #567), so it is understood that the current structure is a bit of a mess. I think just adding a new section to the tokens chapter is probably the best thing to do for now.