Add an example browser package

This contains a base template that may be used for all frontend packages going forward.
This covers:

* Testing, using mocha and mocha-phantomjs via `make test`.
* Linting, using coffeelint via `make lint`.
* Code style (very loosely ensuring consistent newlines and whitespace using EditorConfig.)
* README, an example README with appropriate sections that can be edited as needed.
* Package management via npm using the package.json.