Latest version of net.sf.proguard:proguard-gradle
https://javadoc.io/doc/net.sf.proguard/proguard-gradle
Current version 6.1.0beta2
https://javadoc.io/doc/net.sf.proguard/proguard-gradle/6.1.0beta2
package-list path (used for javadoc generation -link option)
https://javadoc.io/doc/net.sf.proguard/proguard-gradle/6.1.0beta2/package-list