Create new package @apache-annotator/annotation

[Treora]

Types & utility functions for annotations as a whole.

With code imported from https://code.treora.com/gerben/web-annotation-utils.

Unfortunately, I keep getting an error when running yarn test. (even though I think I made this package’s config exactly like the others)

/vagrant/annotator/incubator-annotator/packages/annotation/test/model/multiplicity.test.ts:24
import { strict as assert } from 'assert';
^^^^^^

SyntaxError: Cannot use import statement outside a module