Fix broken links reported by weekly lychee check

[TheDerbiedOne]

Fixes the 4 link-checker 404s reported in #3151:

• Update TiDB Binlog overview links to a version where the page still exists.
• Replace the templated raw GitHub URL with the resolved release branch so the markdown link checker can validate it.

Closes #3151.

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
Once this PR has been reviewed and has the lgtm label, please assign lilin90 for approval. For more information see the Code Review Process.
Please ensure that each of them provides their approval before proceeding.

The full list of commands accepted by this bot can be found here.

Details

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[ti-chi-bot]

Welcome @TheDerbiedOne!

It looks like this is your first PR to pingcap/docs-tidb-operator 🎉.

I'm the bot to help you request reviewers, add labels and more, See available commands.

We want to make sure your contribution gets all the attention it needs!



Thank you, and welcome to pingcap/docs-tidb-operator. 😃

[pingcap-cla-assistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[Oreoxmt]

@TheDerbiedOne Thanks for the contribution!

These changes are already covered by PR #3134, which was opened earlier. To avoid duplication, we'll proceed with that PR and close this one.

Thanks again for your contribution and interest in improving the documentation.