Reorganize source directories

build.gradle

jastadd_modules

src/main/jastadd/Inheritance.jrag

src/main/jastadd/ToJson.jrag

src/main/jastadd/Typenames.jrag

src/main/java/org/extendj/ragdoc/DocTag.java

src/main/java/org/extendj/ragdoc/InlineTagExpander.java

src/main/java/org/extendj/ragdoc/JavaDocParser.java

src/main/java/org/extendj/ragdoc/JsonBuilder.java

src/main/java/org/extendj/ragdoc/RagDocBuilder.java

src/main/java/org/extendj/util/RelativePath.java