tracking eed3si9n/learning-scalaz@a630f3570b0f1ab8ba8f1f4fecfaa666a3d72079

additionally
- started using Sonatype’s javadoc URL
- added notes on Tag.unsubst since Tag.unwrap doesn’t work on REPL
tracking eed3si9n/learning-scalaz@497df73db3fa1a06023fc90d16996370d744690a
tracking eed3si9n/learning-scalaz@3777fcda63698c07e468d5e5c5dde2f223cd1615