Monster layout update, CR filter update, donate button.

• Changed the monster stat appearance
• Improved performance of the CR filter
• Added a donate button to the about page (#39)
• Moved google analytics snippet (#38)

CR Filter

• Filter monster list by CR
• Monster list ordering in decending CR

Favourites

• Adds the ability to add/remove monsters from the list of favourites.
• Favourites are stored client side via localStorage.
• New menu system

v0.1.1

Improvements

• slug on Monster class to fix 404 with monsters with "of" in the name
• improved filtering to not restrict monster list to the subset of the q param in the url