Add description for --log-file parameter

[hfxsd]

What is changed, added or deleted? (Required)

Add description for --log-file parameter, --log-file="-" use to print log to stdout

the --log-file="-" used by DBaaS, however, no doc described what it means.

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

• This PR is translated from:Add description for --log-file parameter docs-cn#7549
• 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:

• Liuxiaozhen12

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[fengou1]

/LGTM

[ti-chi-bot]

@fengou1: Thanks for your review. The bot only counts approvals from reviewers and higher roles in list, but you're still welcome to leave your comments.

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@gozssky: Thanks for your review. The bot only counts approvals from reviewers and higher roles in list, but you're still welcome to leave your comments.

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[Liuxiaozhen12]

/remove-status LGT1
/status LGT2

[Liuxiaozhen12]

/merge

[ti-chi-bot]

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

Commit hash: c692695

[ti-chi-bot]

In response to a cherrypick label: new pull request created: #6914.

[ti-chi-bot]

In response to a cherrypick label: new pull request created: #6915.

[ti-chi-bot]

In response to a cherrypick label: new pull request created: #6916.