Moved the setup and verify aspect of the JDK version into a separate markdown file and back-linked it to the README.md, other modifications to the README.md
Moved the setup and verify aspect of the JDK version into a separate markdown file and back-linked it to the README.md, other modifications to the README.md

neomatrix369/jdk9-jigsaw,AdoptOpenJDK/jdk9-jigsaw,AdoptOpenJDK/jdk9-jigsaw,neomatrix369/jdk9-jigsaw,neomatrix369/jdk9-jigsaw,AdoptOpenJDK/jdk9-jigsaw