redo hella docs scss

- clean out commented out code
- break apart homepage.scss into sub files by component
- rename a few files to reflect their new component names

docs/assets/scss/_zeroclipboard.scss

@@ -1,6 +1,6 @@
+// ZeroClipboard
 //
-// ZeroClipboard styles
-//
+// Flash-based `Copy` buttons for code snippets.
 
 .zero-clipboard {
   position: relative;