Write an overview of the underlying DOMAnnotations library

[nickstenning]

It's likely that Annotator 2.0 will be built on top of a lower-level abstraction, currently being called DOMAnnotations. Write a technical overview of this component, explaining:

• its twofold purpose: as a model of annotations in the current document to support Annotator, and as a straw man proposal for a future user-agent API for annotations on documents
• how to add, update, and remove annotations from the dom
• examples of the different kinds of target classes included in the package (if relevant)
• details of the events fired in the DOM to notify observers of annotation model events

[BigBlueHat]

Like this thing? :wink: https://github.com/nickstenning/domannotations