docs: Clarify how to enable math equations

[waldyrious]

Pre-flight checklist

• I have read the Contributing Guidelines on pull requests.
• If this is a code change: I have written unit tests and/or added dogfooding pages to fully verify the new behavior.
• If this is a new API or substantial change: the PR has an accompanying issue (closes #0000) and the maintainers have approved on my working plan.

Motivation

Typically installation instructions come before usage instructions. The fact that usage section is placed at the top is justified as this may serve as a quick reference to those who have already used the feature before, but a quick note linking to the installation/configuration section will help those who are reading about this for the first time follow the steps in the proper order. This PR adds such a note in a nonintrusive way that doesn't affect the flow of the existing text.

Test Plan

Test links

Deploy preview: https://deploy-preview-10894--docusaurus-2.netlify.app/docs/markdown-features/math-equations

[netlify]

✅ [V2]

Name	Link
🔨 Latest commit	1c6e9ba
🔍 Latest deploy log	https://app.netlify.com/sites/docusaurus-2/deploys/67a0ad9a0089ca0008d8064a
😎 Deploy Preview	https://deploy-preview-10894--docusaurus-2.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[github-actions]

⚡️ Lighthouse report for the deploy preview of this PR

URL	Performance	Accessibility	Best Practices	SEO	Report
/	🟠 59	🟢 98	🟢 96	🟢 100	Report
/docs/installation	🟠 53	🟢 97	🟢 100	🟢 100	Report
/docs/category/getting-started	🟠 73	🟢 100	🟢 100	🟠 86	Report
/blog	🟠 62	🟢 96	🟢 100	🟠 86	Report
/blog/preparing-your-site-for-docusaurus-v3	🟠 64	🟢 92	🟢 100	🟢 100	Report
/blog/tags/release	🟠 62	🟢 96	🟢 100	🟠 86	Report
/blog/tags	🟠 74	🟢 100	🟢 100	🟠 86	Report

[waldyrious]

Thank you for pointing out what the cause of the CI failure was, and fixing it yourself! I didn't understand from the CI logs what it was that prettier was complaining about 😅 Would be possible to make the output a bit more verbose so the actual issues are clearer?

Also, it seems like the CI attempted an autofix for the linter issue, but it failed due to lack of permissions to push to my fork. However, I did have the "Allow edits and access to secrets by maintainers" checkbox ticked (it seems to be unticked now, but I am 100% sure it was before, because I checked it when I saw that CI error). Could it be that the action requires additional permissions so it can act as a maintainer and thus be able to autofix linter issues in external PRs like this?

[slorber]

Would be possible to make the output a bit more verbose so the actual issues are clearer?

This is super annoying but Prettier doesn't provide any solution 😅 prettier/prettier#6885

We may need to create it ourself with some kind of git diff output

The autofix thing only works for internal PRs. Unfortunately I can't make it work for external PRs in a secure way that easily, and it may involve someone from Meta approving an app.

[waldyrious]

This is super annoying but Prettier doesn't provide any solution 😅 prettier/prettier#6885

😮

We may need to create it ourself with some kind of git diff output

Yeah, a git diff would work well IMO. If the log output supports ANSI color escape codes, something like delta would be even better :)