Write a "learn" page or a guide on IO

[puredanger]

This is a place where Clojure relies heavily on Java and having an overview of that would be very helpful

• streams vs reader/writers
• buffered and other kinds of readers
• charsets
• stdin/stdout/stderr
• slurp/spit
• clojure.java.io
• using read, read-line, read-string
• printing is probably a separate page/guide and we have a ticket for that, but maybe just a bit would be useful
• the role of edn

[AlexAti]

In case someone is looking for such a guide, part of the mentioned content is freely available at https://freecontent.manning.com/dive-into-clojure-java-io/ from the upcoming "Clojure, The Essential Reference" book by Renzo Borgatti (@reborg).