cdc: add description about the checksum v2

[3AceShowHand]

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• This PR is translated from: cdc: add description about checksum v2 docs-cn#18273
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• Delete files
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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-09-23 08:01:14.086331625 +0000 UTC m=+1466543.826755564: ☑️ agreed by Oreoxmt.
• 2024-09-27 08:14:59.254579705 +0000 UTC m=+1812968.995003644: ☑️ agreed by qiancai.

[Oreoxmt]

/approve
/unhold

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

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[purelind]

/hold

[purelind]

/test all

[purelind]

/unhold