Documentation for usage with spotless gradle/maven plugin

[atomfrede]

Spotless does support prettier and mentions prettier for java. Maybe we should provide examples how to configure spotless with prettier for java.

• https://github.com/diffplug/spotless/tree/main/plugin-gradle#prettier-plugins

[pascalgrimaud]

It has been discussed here #469 (comment) by @jqno

[jqno]

I adapted my configuration from the documentation over at the Spotless GitHub page

In my comment I refer to these lines in the EqualsVerifier pom. Note that only the first <include> will be necessary for most people: <include>src/*/java/**/*.java</include>. I have an uncommon setup for some unit tests that are specific for certain Java versions (e.g. tests for Java 16's record feature).