Fix #2777 - Improvement request- Problems with some Katex functions

[MiloTodt]

Description

Issue found to be an out of date Katex module, after update these symbols now work.
Updated Katex module from 0.9.0 -> 0.10.0

Issue fixed

fix #2777
$\real$ now working as requested.

Type of changes

• ⚪ Bug fix (Change that fixed an issue)
• ⚪ Breaking change (Change that can cause existing functionality to change)
• 🔘 Improvement (Change that improves the code. Maybe performance or development improvement)
• ⚪ Feature (Change that adds new functionality)
• ⚪ Documentation change (Change that modifies documentation. Maybe typo fixes)

Checklist:

• 🔘 My code follows the project code style
• ⚪ I have written test for my code and it has been tested
• ⚪ All existing tests have been passed
• 🔘 I have attached a screenshot/video to visualize my change if possible

Upgrading Katex module has caused previous test for it to fail.
Suggest updating the markdown-test.js.snap snapshot to reflect the new version of Katex.
The 'vulnerable libraries' that guardrails is objecting to were present in package.json before this change.

[guardrails]

No more findings on this branch.
This means you fixed everything we detected earlier. Good job!! 👍🎉

We will keep this comment up-to-date as you go along and notify you of any security issues that we identify.

Happy with the results? Give your feedback.

[ZeroX-DG]

We use yarn instead of npm so please re-install the dependency using yarn

[MiloTodt]

Katex 0.10.0 now installed with yarn instead of npm

[ZeroX-DG]

LGTM 🎉

[ZeroX-DG]

I'm really sorry @MiloTodt but there's already a PR before this one: #2576. Thank you for your contribution anyway!