Update changelog for Maven plugin

Author: lutovich

plugin-maven/CHANGES.md

@@ -5,6 +5,7 @@
 * Fixed a bug in `LicenseHeaderStep` which caused an exception with some malformed date-aware licenses. ([#222](https://github.com/diffplug/spotless/pull/222))
 * Added support for Kotlin and Ktlint in Maven plugin ([#223](https://github.com/diffplug/spotless/pull/223)).
 * Updated default ktlint from 0.14.0 to 0.21.0
+* Added support for multiple generic formatters in Maven plugin ([#242](https://github.com/diffplug/spotless/pull/242)).
 
 ### Version 1.0.0.BETA4 - February 27th 2018 ([javadoc](https://diffplug.github.io/spotless/javadoc/spotless-maven-plugin/1.0.0.BETA4/), [jcenter](https://bintray.com/diffplug/opensource/spotless-maven-plugin/1.0.0.BETA4))