added optional download

Added the option to download the game. The downloadable version will be the main one that gets updated because it has features that aren't compatible with the browser version.

New stuff

* Monsters will drop cards that can be collected to view monster info (Viewable by pressing N)

* Updated save system - the game will create and read save files to and from your computer.

* Adjustments to the assassinate skill
    - Visual changes
    - Damage numbers are now stacked on top of each other for better readability 
    -  Sped up animation

* Various bug fixes