Update some comments #486

Job	Run time
Bitrot check	1m 32s
Test on ubuntu-latest	10m 52s
Test on i686-unknown-linux-gnu	21m 33s
Test on windows-latest	14m 8s
Build target wasm32-unknown-unknown	2m 20s
Test on i686-unknown-linux-gnu with beta features	21m 34s
Test on macOS-latest	8m 15s
Build target wasm32-wasi	2m 14s
Test on i686-unknown-linux-gnu with nightly features	21m 50s
Test on ubuntu-latest with beta features	10m 40s
Test on windows-latest with beta features	14m 13s
Test on macOS-latest with beta features	8m 14s
Book tests	1m 57s
Intra-doc links	2m 1s
Test on ubuntu-latest with nightly features	10m 49s
Test on windows-latest with nightly features	14m 33s
Rustfmt	15s
Test on macOS-latest with nightly features	8m 24s
	2h 55m 24s

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