Steven G. Johnson

It would be nice to have an `hcubature_count` function analogous to `quadgk_count`, which returns the number of integrand evaluations. Very easy to implement, see https://discourse.julialang.org/t/hcubature-count/115878/2?u=stevengj

Might be nice to have the function `\underline{x}`, analogous to https://github.com/matplotlib/matplotlib/issues/14235 (e.g. https://tex.stackexchange.com/questions/75745/how-do-you-write-a-vector-with-an-underline-instead-of-an-arrow)