this adds `hilbish.opts`, a table to set
simple options akin to shopt or setopt on
other shells. this commit specifically also
includes the autocd opt, which functions the
way you expect it to
to set opts, simply do `hilbish.opts.name = val`,
where `name` is the opt you want to set and `val`
being the opt setting.
ie: `hilbish.opts.autocd = true` to turn on autocd
TorchedSammy
