Produce pages with speech output from SRE

[rbeezer]

A feature request for the mjpage command-line tool. Allow options for speech-rule-engine to be specified, and get back a page where all the math parts have been replaced by a speech string, wrapped in a predictable span, or similar, like how it happens now for other types of output. But not all the MathML or SVG or anything else. My use would be further processing of the page, if this seems like an oddly designed page to be expecting as a result.

With the help of @pkra and @zorkow I have mathjax-node-sre doing what I need right now, so there is no urgency in this request.

[pkra]

This would probably require to use mathjax-node-sre by default which seems ok to me.

As I wrote elsewhere, mathjax-node-page hasn't seen a lot of interest lately and could really use a complete refactor, e.g., switching to async/await would be an obvious simplification.

It might just be time to revise the entire library and start basing it on mathjax 3, cf. the demos at https://github.com/mathjax/mj3-demos-node.