Missing optional fields require a type to be explicitly provided as
it cannot be inferred from the payload. Ignored fields are not
included in the documentation, yet, previously, a field that was
missing, optional, and ignored would still require a type to be
provided otherwise the test would fail. This was pointless as the
field wasn't going to appear in the documentation.
This commit updates the fields snippets so that a type is no longer
required for a field that is missing, optional and ignored.
Closes gh-289
9ba0a9b6be