With EV3 dropped from the 3.X documentation, the main docs are now nearly identical to the IDE docs, save for some layout changes.
Having just one set of docs is easier to maintain. This drops the IDE doc target.
MathJax uses a CDN to to distribute the package. So in order to use the
docs offline, we would have to include our own copy. But it is a bit
large (50-ish MB), so it is easier to use sphinx.ext.imgmath instead
to generate svg images.
The situation might be different with MathJax v3, but that requires
Sphinx v4.