Fix references to companion QUIC drafts

[janaiyengar]

Closes #808

[martinthomson]

This won't work. It will cause quic-http-05 to reference quic-transport-04.

The template has the ability to generate the right anchors as necessary for submission, but I haven't checked that it works properly. I'll double-check when I get the chance.

BTW, I have a new submission process, which should remove some of the human error factors. The code that generates the right tags has been recently updated (since the -06 drafts were submitted).

[martinthomson]

I am fairly confident now that my new code correctly changes any instances of draft-foo-latest when building for submission.

I didn't include a link before, but here are the new instructions. Be careful to note the use of git tag -a, which creates an annotated tag.