Add blockquote to MessageEntityType #724

Job	Run time
rustfmt	11s
Test stable ubuntu-latest --no-default-features	1m 38s
Test stable ubuntu-latest	2m 2s
Test stable ubuntu-latest --all-features	4m 4s
Test stable macos-latest --no-default-features	4m 52s
Test stable macos-latest	3m 23s
Test stable macos-latest --all-features	3m 0s
Test stable windows-latest --no-default-features	3m 14s
Test stable windows-latest	3m 46s
Test stable windows-latest --all-features	4m 44s
Test beta ubuntu-latest --all-features	2m 3s
Test nightly ubuntu-latest --all-features	2m 3s
Release x86_64-unknown-linux-gnu	1m 3s
Release aarch64-unknown-linux-gnu	1m 6s
Release armv7-unknown-linux-gnueabihf	1m 14s
Release arm-unknown-linux-gnueabihf	1m 13s
Release riscv64gc-unknown-linux-gnu	1m 11s
Release x86_64-apple-darwin	1m 23s
Release aarch64-apple-darwin	2m 5s
Release x86_64-pc-windows-msvc	2m 44s
Release aarch64-pc-windows-msvc	2m 30s
	49m 29s

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