docs: Properly link to custom clang-tidy plugin instructions

[RobbieNeko]

Checklist

Required

• I wrote the PR title in conventional commit format.
• I ran the code formatter.
• I linked any relevant issues using github keyword syntax so it can be closed automatically.
• I have committed my changes to new branch that isn't main so it won't cause conflict when updating main branch later.

Purpose of change

Docs hasn't been deploying since approximately 3 months ago, meaning any documentation changes in the meantime just never showed up on the website.

Describe the solution

Fixes the invalid link by properly linking to it instead of trying to do a relative path.

Describe alternatives you've considered

• Let Scarf know and have him fix it
• Weh

Testing

Unable

Additional context

I find it really funny that Scarf literally made the docs, but also made the PR that stopped them from deploying for 3 months

[autofix-ci]

Autofix has formatted code style violation in this PR.

I edit commits locally (e.g: git, github desktop) and want to keep autofix

1. Run git pull. this will merge the automated commit into your local copy of the PR branch.
2. Continue working.

I do not want the automated commit

1. Format your code locally, then commit it.
2. Run git push --force to force push your branch. This will overwrite the automated commit on remote with your local one.
3. Continue working.

If you don't do this, your following commits will be based on the old commit, and cause MERGE CONFLICT.

[scarf005]

weird that broken link bork the whole pipeline