Update documentation to use MathML

[jabagawee]

Description

The current implementation of the documentation is somewhat inconsistent with math notation. A few examples:

1. Matrices currently vary between having and not having commas to separate elements:
   a. (without commas) https://threejs.org/docs/#api/en/math/Matrix4.makeRotationFromQuaternion
   
   b. (with commas) https://threejs.org/docs/#api/en/math/Matrix4.makeBasis
   

2. Some pages are inconsistent even within the same example:
   a. https://threejs.org/docs/#api/ar/math/Matrix4.makeBasis utilizes both Arabic commas and regular commas.
   

3. Alignment inconsistencies:
   a. (center aligned) https://threejs.org/docs/#api/en/math/Matrix4.makeBasis
   
   b. (left-ish aligned): https://threejs.org/docs/#api/en/math/Matrix4.makeRotationZ
   

4. Some sections do not have the correct formatting:
   a. https://threejs.org/docs/#api/en/math/Matrix4.makeRotationY
   

Solution

I propose that we replace the math markup throughout the documentation with MathML, which is accepted by all major browsers (according to mdn and caniuse).

Alternatives

The alternative would be to format the <code> sections in the documentation more carefully, but I'm not so sure that this is a superior alternative.

Additional context

No response

[Mugen87]

Do you mind updating one of the code examples on a new branch with MathML so we can easier make a comparison?

[jabagawee]

Is it possible to re-open issues, or do I need to file a new one? We can perform some more substitutions for MathML in the page for Matrix3. I haven't checked the docs for other pages yet, but I imagine other pages in the math/ subdirectory might also benefit.

[Mugen87]

It's okay to keep the issue open until other docs pages have been updated. It was automatically closed because #26887 got merged.

[Mugen87]

I've went through the math pages and could not find more obvious places where a migration to MathML is required. I think we can close this issue now.

For the future we can keep the policy in mind to always use MathML if we want to format math related syntax in the documentation or other places. If someone spots a place where MathML would make sense, it's best to directly file a PR. A separate issue isn't relevant in this case.