Delete `.DS_Store` nonsense file

You should add this to your global Git ignore list. But for now…
Merge pull request #6 from markjaquith/patch-1

Delete `.DS_Store` nonsense file
Bumping example font sizes to increments of 20

Since dashicons are created on a 20px grid, not a 16px grid, they
should be displayed accordingly so they appear crisp and clean on lower
resolution screens.
Merge branch 'master' into gh-pages