nginx to 1.25.1, other updates, and update docs and configs.

[justdan6]

nginx to 1.25.1 and using nginx mainline as opposed to the quic branch
alpine to 3.17
BoringSSL and NJS to the most recent commit
http2 directive used
update docs and configs

#110

[macbre]

@justdan6 - thanks for this PR!

We just need to change the tests as they assume certain response headers to be present:

<p>It works!</p>
+ grep --fixed-strings '< HTTP/3 200' /tmp/h3
< HTTP/3 200
+ grep --fixed-strings --invert-match -i '< server: nginx' /tmp/h3
+ grep --fixed-strings '< alt-svc: h3-27=":8889"; ma=86400, h3-28=":8889"; ma=86400, h3-29=":8889"; ma=86400' /tmp/h3

[macbre]

@justdan6 - thanks. Merging and will tag it later today.