Feature: Add tag parameter to field objects

[sheppy-atai]

Sometimes we add new parameters (or result fields) to our existing APIs. We would like to be able to put a tag next to the name of the field indicating the version of our product in which that field was added. For example:

<ParamField path="file_type" tag="v1.1.2+" type="string">
  Filters results to the specified MIME file type.
</ParamField>

This would generate something like: