Issue: junit-team#3139 Add external diff module to module documentation

Add external diff module  to module documentation
For unknown reason, the test cases can not find the external module while the gradle can build normally.

Issue: junit-team#3139

junit-platform-console/src/module/org.junit.platform.console/module-info.java

@@ -20,6 +20,7 @@
 	requires org.junit.platform.engine;
 	requires org.junit.platform.launcher;
 	requires org.junit.platform.reporting;
+	requires io.github.javadiffutils;
 
 	provides java.util.spi.ToolProvider with org.junit.platform.console.ConsoleLauncherToolProvider;
 }