Merge pull request #8 from brittanydmiller/frontend

Frontend
Tweaks copy phrasing in header and form
Creates an 'about' div with a link in the header, next to github link
Basic styles / content for output & metrics divs
Fixes bug where DOM elements are measured before they exist.
Rename to Ding\n
Changes hidable to hideable, input to user-input, output-class to output-box, and adds/styles a footer
Add list li elements for the labels in the input form
Adds a reset link, fleshes out metrics content
Gets styling to basic acceptable level for desktop viewing
Hides input form when submitting a Ding
Reduces size of bg image