Either and Result monadic types for Java

* finish docs (particularly package docs, usage examples)
* nice intro (with synopsis and short examples)

depend via Maven:

<dependency>
  <groupId>net.xyzsd</groupId>
  <artifactId>dichotomy</artifactId>
  <version>0.9</version>
  <type>module</type>
</dependency>

or Gradle:

implementation("net.xyzsd:dichotomy:0.9")

Copyright 2022, xyzsd

Licensed under either of:

• Apache License, Version 2.0 (see LICENSE-APACHE or http:https://www.apache.org/licenses/LICENSE-2.0)
• MIT license (see LICENSE-MIT) or http:https://opensource.org/licenses/MIT)

at your option.