Modernized javadocs to html5

Upgraded build to JDK11, but still targeting Java 8. Purpose is to use the JDK11 javadoc to modernize documentation, such as with search and no frames.

Author: cicirello

.github/workflows/maven-publish.yml

@@ -19,10 +19,10 @@ jobs:
       id: get_version
       run: echo ::set-output name=VERSION::${GITHUB_REF/refs\/tags\/v/}
 
-    - name: Set up JDK 1.8 for deploy to OSSRH
+    - name: Set up JDK 11 for deploy to OSSRH
       uses: actions/setup-java@v1
       with:
-        java-version: 1.8
+        java-version: 1.11
         server-id: ossrh 
         server-username: MAVEN_USERNAME
         server-password: MAVEN_CENTRAL_TOKEN
@@ -42,10 +42,10 @@ jobs:
         MAVEN_CENTRAL_TOKEN: ${{ secrets.MAVEN_CENTRAL_TOKEN }}
         MAVEN_GPG_PASSPHRASE: ${{ secrets.MAVEN_GPG_PASSPHRASE }}		
 
-    - name: Set up JDK 1.8 for deploy to github packages
+    - name: Set up JDK 11 for deploy to github packages
       uses: actions/setup-java@v1
       with:
-        java-version: 1.8
+        java-version: 1.11
         server-id: github 
 
     - name: Publish to GitHub Packages Apache Maven