Add description for auto detect mode of online recovery

[Oreoxmt]

What is changed, added or deleted? (Required)

Add the description of auto-detect parameter, which is used when you cannot confirm the store ID.

Which TiDB version(s) do your changes apply to? (Required)

Tips for choosing the affected version(s):

By default, CHOOSE MASTER ONLY so your changes will be applied to the next TiDB major or minor releases. If your PR involves a product feature behavior change or a compatibility change, CHOOSE THE AFFECTED RELEASE BRANCH(ES) AND MASTER.

For details, see tips for choosing the affected versions.

• master (the latest development version)
• v6.2 (TiDB 6.2 versions)
• v6.1 (TiDB 6.1 versions)
• v5.4 (TiDB 5.4 versions)
• v5.3 (TiDB 5.3 versions)
• v5.2 (TiDB 5.2 versions)
• v5.1 (TiDB 5.1 versions)
• v5.0 (TiDB 5.0 versions)

What is the related PR or file link(s)?

• This PR is translated from: Add description for auto detect mode of online recovery docs-cn#10979
• 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]

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[Oreoxmt]

/status LGT1

[Oreoxmt]

/rebase

[Oreoxmt]

/type enhancement

[qiancai]

Removed the needs-cherry-pick-release-6.3 label because the v6.3 docs have been archived at https://docs-archive.pingcap.com/tidb/v6.3 and will no longer receive new updates.

[qiancai]

Removed the needs-cherry-pick-release-6.4 label because the v6.4 docs have been archived at https://docs-archive.pingcap.com/tidb/v6.4 and will no longer receive new updates.

[qiancai]

Removed the needs-cherry-pick-release-6.6 label because the v6.6 docs have been archived at https://docs-archive.pingcap.com/tidb/v6.6 and will no longer receive new updates.

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

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[qiancai]

Removed the needs-cherry-pick-release-7.0 label because the v7.0 docs have been archived at https://docs-archive.pingcap.com/tidb/v7.0 and will no longer receive new updates.

[qiancai]

Removed the needs-cherry-pick-release-7.2 label because the v7.2 docs have been archived at https://docs-archive.pingcap.com/tidb/v7.2 and will no longer receive new updates.

[qiancai]

Removed the needs-cherry-pick-release-7.3 label because the v7.3 docs have been archived at https://docs-archive.pingcap.com/tidb/v7.3 and will no longer receive new updates.