Add searchable descriptors

[komizutama]

items like, "gluten-free", "dairy-free", "parve", "kosher", "vegan" etc. Look at the Mean Database and plentiful as examples

[Grantimus9]

Here's the MEANS taxonomy -> not comprehensive, but worth making sure they're all covered.

A temptation we've had is creating a decision-treet of questions, e.g. if a user selects "veggies" asking them if it's also gluten-free, but once we sat down to define the taxonomy realized it's awful flat and wouldn't save much screen space or improve the ux as much as we thought it would.