Add test for Chemistry

[GeorgeKerscher]

MathML 4.0 supports adding intent for Chemistry in the markup. We have agreed to put the tests for MathML into the fundamental test books. When the Chemistry isprovided through MathML, it would also present this information. However, the reading of the Chemistry may not be equally supported. For this reason, I would like to see a separate test for the presentation of Chemistry within MathML.

[ways2read]

A possible way to include inline and block chemistry in the 2024 revisions. We could move this into 2023 if we discover the support is here now.

MathML 4 is coming the new features can go into an experimental book.

[GeorgeKerscher]

Adding the label experimental.

[GeorgeKerscher]

adding experimental label.