Add a code of conduct #98

Job	Run time
Audit dependencies	25s
Format	6s
Build and test (stable, ubuntu-latest, x86_64-unknown-linux-gnu)	1m 12s
Clippy (x86_64-unknown-linux-gnu, false, true)	1m 52s
Clippy (armv7-unknown-linux-gnueabihf, true, false, -target arm-linux-gnueabihf -mcpu=generic+v7a...	29s
Build and test (beta, ubuntu-latest, x86_64-unknown-linux-gnu)	2m 2s
Smoke-test fuzzing targets	3m 50s
Validate man pages	9s
Clippy (x86_64-unknown-linux-musl, true, false, -target x86_64-linux-musl)	44s
Build and test (1.66.0, ubuntu-latest, x86_64-unknown-linux-gnu)	1m 11s
Smoke-test fuzzing targets (--all-features)	1m 38s
Clippy (x86_64-apple-darwin, true, false, -target x86_64-macos-gnu -g)	22s
Build and test (stable, ubuntu-latest, x86_64-unknown-linux-musl)	1m 55s
Check unused dependencies	1m 42s
Build and test (stable, macos-latest, x86_64-apple-darwin)	2m 15s
Validate configs	1m 23s
Build and test (stable, ubuntu-latest, --all-features, x86_64-unknown-linux-gnu)	1m 53s
Build and test (1.66.0, ubuntu-latest, --all-features, x86_64-unknown-linux-gnu)	1m 10s
Build and test (stable, ubuntu-latest, --all-features, x86_64-unknown-linux-musl)	1m 1s
Build and test (stable, macos-latest, --all-features, x86_64-apple-darwin)	1m 50s
	27m 9s

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