Support descriptions in Javadoc rather than comments

Is your feature request related to a problem? Please describe.
As a part of issue #84 support was added to take GraphQL schema comments and output them into generated types. This does not currently support descriptions.

Describe the solution you'd like
According to the GraphQL Spec: §2.1.4 comments are not intended for proper documentation of the API.

Comments behave like white space and may appear after any token, or before a line terminator, and have no significance to the semantic meaning of a GraphQL Document.

The proposed change is to use descriptions instead for Javadoc documentation, as this is consistent with GraphQL Spec: §3.3 and the usage of introspection.

To allow GraphQL service designers to easily publish documentation alongside the capabilities of a GraphQL service, GraphQL descriptions are defined using the Markdown syntax.

Describe alternatives you've considered
It is possible that a generation flag could allow customizing between whether comments or descriptions are used for the Javadoc (and to allow backwards compatibility).

[kobylynskyi]

@mhuffman-r7 Thanks for your feature request.
Version 3.0.0 was released today.
GraphQL descriptions are now considered when generating Javadoc.
Please note: If no GraphQL description is present for the given GraphQL type/field/interface/union/etc then GraphQL comment will be used.

@kobylynskyi Awesome. Thanks so much for the speedy turn-around.