tiflash: fix a rendering error

[shichun-0415]

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What is changed, added or deleted? (Required)

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For details, see tips for choosing the affected versions.

• master (the latest development version)
• v7.0 (TiDB 7.0 versions)
• v6.6 (TiDB 6.6 versions)
• v6.5 (TiDB 6.5 versions)
• v6.4 (TiDB 6.4 versions)
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What is the related PR or file link(s)?

• This PR is translated from: tiflash: fix a rendering error docs-cn#13276
• Other reference link(s):

Do your changes match any of the following descriptions?

• Delete files
• Change aliases
• Need modification after applied to another branch
• Might cause conflicts after applied to another branch

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• Oreoxmt

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[Oreoxmt]

LGTM

[shichun-0415]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: c3205e3

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-6.6: #12748.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-6.5: #12749.