Add Test to Read Aloud for MathML

We should do both inline and block math just like our Math test book.
One test should include Horizontal lines separating the block mathml like our math test book.
Another test for inline should not include the lines separating out the math as that can cause a different experience as was found where all text between the two horizontal lines were skipped by a reading system. Would not want to conflate two different issues with one test.

Start by locating the existing Math test book and comparing how it covers inline and block math. Add separate read-aloud coverage for both forms, keeping horizontal separators only around block MathML and omitting them from inline MathML. Done means both cases are represented without combining their reading-system behaviors.

Written by the indexing model from the issue text.