breaking: fix main package entry

[brodybits]

The following main entry in package.json only exports lib/dom-parser.js:

  "main": "lib/dom-parser.js",

I think the main package object should provide access to functionality of all modules in lib.

May be related to: #40, #48

[karfau]

To clarify the status: #233 deprecated the redundant exports in lib/dom-parser.js, they will be dropped from the module in the next breaking release, which will resolve this issue.