http: docs deprecation of 418 teapot status
Docs-only deprecation of the I'm a teapot
status for 9.x, with the intent of removing the unregistered status code by 10.x
Fixes: https://github.com/nodejs/node/issues/14644
/cc @mnot
Checklist
-
make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
tests and/or benchmarks are included -
documentation is changed or added -
commit message follows commit guidelines