when `format = "latex"`, support exempting macro arguments, subscripts, etc from spellcheck?

[tyner]

Perhaps I am misunderstanding the precise intricacies of format = "latex" but curious to hear your thoughts on these.

This is not flagged (yay!)

hunspell::hunspell(c("\\hline & \\begin{tabular}{lll}"), format = "latex")

On the other hand this (the lll) is flagged:

hunspell::hunspell(c("\\endfoot & \\begin{tabular}{lll}"), format = "latex")

Likewise, these (the itemsep, partopsep, topsep) are all flagged:

hunspell::hunspell("\\begin{itemize}[itemsep=0pt,partopsep=0pt,topsep=0pt]", format = "latex")

Moreover, these (jk and kj) are flagged:

hunspell::hunspell("\\pi_{jk} &= \\frac{\\phi_{kj}}{\\phi_k}", format = "latex")

Thank you for considering.