feat: support Math in Markdown

[lumirlumir]

Prerequisites checklist

• I have read the contributing guidelines.

What is the purpose of this pull request?

This PR updates Code Explorer to support the Math parsing option for the Markdown language, introduced in eslint/markdown#617 and released as part of @eslint/markdown v8.

What changes did you make? (Give an overview)

I've also updated e2e-tests/options.test.ts to test various language options which was previously missing, as well as the test for newly added Math option. I've also used test.step to clearly indicate the current step in the e2e test.

Related Issues

Ref: eslint/markdown#331

Is there anything you'd like reviewers to focus on?

N/A

[netlify]

✅ Deploy Preview for eslint-code-explorer ready!

Name	Link
🔨 Latest commit	8881315
🔍 Latest deploy log	https://app.netlify.com/projects/eslint-code-explorer/deploys/69cb48f4573dd1000884fd41
😎 Deploy Preview	https://deploy-preview-299--eslint-code-explorer.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 project configuration.

[ayatobai]

@lumirlumir, I wanted to share some constructive feedback on your PRs:

1. I’ve noticed that refactors and fixes/features are sometimes combined in the same PR. Splitting these into separate PRs would make the logic changes easier to review and merge.
2. Tasks like this one seem to be taking a few hours, where I’d expect something closer to ~30 minutes. I’d suggest utilizing AI tools for the boilerplate and tests to help speed things up.