Clarify how else when works

[Cifram]

It turns out ChatGPT, the default interpreter for DreamBerd, tends to assume that the else keyword does nothing, and thus interprets else when as being the same as a simple when. Therefore, to maximize the odds that ChatGPT will correctly understand the semantics of else when, this assumption has been codified. The else keyword now officially does nothing.

This is reflected in the docs, and the official FizzBuzz example.

[Cifram]

This addresses issue #107.