Correct some minor typos in README.md #2944

Job	Run time
cross (i686-unknown-linux-gnu)	2m 0s
cross (aarch64-unknown-linux-gnu)	2m 10s
test (stable, ubuntu-latest, stable)	2m 51s
cross (powerpc-unknown-linux-gnu)	2m 9s
cross (s390x-unknown-linux-gnu)	2m 11s
cross (powerpc64-unknown-linux-gnu)	2m 18s
test (nightly, ubuntu-latest, nightly)	2m 49s
test (win-msvc, windows-latest, stable)	6m 27s
testfull-regex-automata	7m 28s
test (beta, ubuntu-latest, beta)	2m 45s
test (macos, macos-latest, stable)	2m 47s
testfull-regex-capi	29s
testfull-regex-syntax	1m 43s
msrv	5m 36s
docsrs	32s
test (win-gnu, windows-latest, stable-x86_64-gnu)	3m 4s
miri-regex-automata	11m 5s
rustfmt	15s
testfull-regex	2m 47s
	1h 1m 26s

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