Add example showing how to use hyper's low level API #4036

Job	Run time
check	54s
check-docs	37s
cargo-hack	3m 18s
cargo-public-api-crates (axum)	34s
dependencies-are-sorted	17s
cargo-public-api-crates (axum-core)	29s
cargo-deny check (advisories)	26s
cargo-deny check (bans licenses sources)	22s
Spell Check with Typos	5s
cargo-public-api-crates (axum-extra)	36s
cargo-public-api-crates (axum-macros)	25s
test-versions (stable)	2m 16s
test-versions (beta)	2m 14s
test-docs	1m 48s
test-msrv	1m 45s
armv5te-unknown-linux-musleabi	44s
test-nightly	1m 49s
wasm32-unknown-unknown	37s
	19m 16s

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