Minor cleanup / whitespace changes for readability
Added collapsible option

 - Previously showDescription was used to indicate if the sections were
   collapsible or not. But it also hid the descriptions if it was true, and when
   you clicked to expand the item you would only see whitespace. Now
   showDescription simply does that, and the new collapsible option
   determines if the descriptions can be closed or not. (also aligns it a
   bit close to the accordion api)
Only display link button if url exists

 - If you dont provide a url in the data (because all the information is
   contained on the single page), the "click to view" button will no
   longer be generated
Remove day highlight when selecting the month

 - Clicking on the month to display all events for that month will now
   remove the highlighted day
Fixed style issues with the description

 - Changed the description content from being in a paragraph to a div to
   fix issues with styling and 'bouncing' in the sliding effects
Added the readme