NPM package & cleaner interface.

[seanmorris]

• Allows users to access PHP by hanging event listeners on object
• Creating ES6 module for NPM distribution
• Move documentation into docs/ folder
• Create git precommit hook to build project and update docs on commit.

[oraoto]

Amazing work!

Build artifacts (docs/php-web.*) should be ignored. We can setup CI later to provide these files.

[seanmorris]

If we ignore the files in docs, they won't be available to Github Pages.

Rather than using the root of the project, github also allows user to put the files under docs/ .