MathML-Core support shipped by default in chromium 109

[bkardell]

docs in a few places suggest that some things will only work in Firefox and Safari, but now that everything is based on these or Chromium and Chromium now has support this is perobably not true anymore.

[aslakr]

Related issue on the asciimath.org website asciimath/asciimath.github.io#31

[runarberg]

Note that MathML-Core is a significant subset of the MathML which AsciiMath targets. There are notable deprecated features. Most notably is the mathvariant attribute which is deprecated for everything except normal, so e.g. bbb for double-struck won’t work without a polyfill. Another example is <menclose> which is currently missing from MathML-Core and is used for cancel.

<mstyle> and mathcolor are also not apart of MathML-Core, at least not how AsciiMath uses it, however it is implemented in Chrome and unlikely to cause issues for browsers.

In my competing authoring tool I’ve had to deal with quite a few of these incompatibilities and I still have a few left. It is safe to say that chrome is still not fully supported until I finish those.