fields can't include examples

[dustmop]

Trying to use examples for a field results in a parsing error:

unexpexted token: examples: examples 6 3

But even if it parsed, fields are displayed in a terse table with no room for examples. This is usually fine when fields are simple data values. However, for dataframes, I'm using fields to represent attributes which are actually pretty complex and require a bit of explanation. The proper fix is probably implementing a category for attributes, rather than trying and failing to use fields instead.