xilem: Docs updating #2602

Job	Run time
cargo check (aarch64-android)	25s
cargo check (msrv) (windows-latest)	1m 43s
cargo check (msrv) (wasm32)	21s
cargo check (msrv) (macos-latest)	50s
cargo clippy (windows-latest)	5m 1s
cargo clippy (wasm32)	2m 4s
cargo clippy (macos-latest)	2m 5s
cargo check (msrv) (ubuntu-latest)	52s
cargo doc	39s
cargo clippy (ubuntu-latest)	3m 16s
formatting	33s
Prime LFS Cache	3s
cargo test (wasm32)	19s
typos	5s
cargo test (windows-latest)	3m 20s
cargo test (macos-latest)	2m 19s
cargo test (ubuntu-latest)	3m 6s
	27m 1s

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