The metadata section contains optional semantic information such as the author
of a file, and the license it is distributed under. It also contains information
looked at by the compiler like other modules it requires. Keys are represented
by name tokens, and values by string tokens. Each key/value pair should be on
its own line, un-indented.
An example metadata section looks like this:
:arf
author "Sasha Koshka"
license "GPLv3"
require "io"