Optionally display descriptor next to producer

[rmeritz]

Addresses issue: https://github.com/bocoup/blocks-capacity-planner/issues/4

• Add an additional "descriptor" selection to the producer settings
• Using "descriptor" instead of "cuisine" so in the setting any text description for a producer could be shown, though the feature was initially requested to show the cuisine
• Change the producer statistics dropdown to be a producer display dropdown. Add "descriptor" as one of the options.
• When the "descriptor" is chosen as a display option display inline on the AssignmentItem

This is what it looks like on the with the example base:

[rmeritz]

@jugglinmike - It would be great if you could take a look at this when you had a chance.

[jugglinmike]

Nice work, Rebecca!