WARNING: dvisvgm command 'dvisvgm' cannot be run

[NickVolynkin]

What needs to be done

In make json logs:

WARNING: dvisvgm command 'dvisvgm' cannot be run (needed for math display), check the imgmath_dvisvgm setting

Looks like we need an extra dependency in our builder image and a few lines in conf.py

See https://www.sphinx-doc.org/en/master/usage/extensions/math.html

Reviewer: @NickVolynkin

Definition of done

• no such warning in the build logs
• imgmath formulas look fine in the docs

[patiencedaur]

Closed by tarantool/doc-builder#16.