Add Pikaday gem to README
Thank you so much for creating the pikaday datepicker.
Since we're working on a Ruby on Rails project we've created an open-source gem which bundles it.

You can find it at https://rubygems.org/gems/pikaday-gem
Source code is at https://github.com/ets-berkeley-edu/pikaday-gem
And readme at https://github.com/ets-berkeley-edu/pikaday-gem#readme

It relies on the fact that you're tagging new versions. So far there is only `1.0.0` but we're already looking forward to the next one.

We'll also version our gem in the following way.
The first 3 (x.x.x) will be the same as your version, while the last digit (_._._.x) will be gem updates.

Hope you'll like it.
Add project configuration files.

Had to make small changes to be jshint compliant.
Make RoR gem advertisement stand out more.
Change production ready statement.
Update README.md

Switch to reference links style.
Emulate GFM in extensions section.
Move changelog to a dedicated file.
Merge pull request #49 from rikkert/config

Add project configuration files.