work around maven complaint about missing sources/javadoc

Author: valters

LawDiff-app/src/main/java/io/github/valters/lawdiff/app/NoSourcesYet.java

@@ -0,0 +1,5 @@
+package io.github.valters.lawdiff.app;
+
+/** make sure sources/javadoc artifact get generated. remove when actual sources are added */
+abstract class NoSourcesYet {
+}