introduce both 1.1 and 2.0

[reschke]

The introduction should reference the currently defined wire formats (1.1 and 2, also 1.0 maybe).

We also need to figure out whether and where to mention differences:

• expect/continue
• transfer codings
• status phrase

[mnot]

Also, the current introduction to all three documents says:

HTTP is defined by a series of documents that collectively form the HTTP/1.1 specification

That needs to be adjusted to something like:

HTTP is defined by [semantics] and [caching], and is mapped to specific wire protocols as versions; currently, [http/1.2] and [http/2] are defined.

[MikeBishop]

HTTP is defined by [semantics] and [caching], and is mapped to specific wire protocols as versions; currently, [http/1.2] and [http/2] are defined.

HTTP/1.2? Is there something you need to share with the working group, @mnot? 😉

[royfielding]

I think (but am not sure) that this has been covered by the changes made in #416

Maybe @MikeBishop and @martinthomson could have a look and see if the short HTTP/2 and HTTP/3 descriptions need more flowers.

[martinthomson]

I think that the number of flowers (->0) is entirely appropriate and I would be happy with those descriptions, with maybe a small tweak to the HTTP/3 text.

[mnot]

I left a review; once we resolve comments on the PR, I think this can be closed.