21.0

This release updates graphql-java to v21.0 and as a result, this library now requires Java 11 as a minimum version.

See the blog announcing the change for graphql-java.

What's Changed

• docs: readme makeover by @setchy in #94
• docs: update version by @setchy in #106
• Bump com.graphql-java:graphql-java from 20.2 to 20.3 by @dependabot in #108
• Update to Java 11, Gradle 8.3, GraphQL Java v21.0 by @dondonz in #113

Full Changelog: 20.2...v21.0