Revert "Using 20px for code padding, 10 was too little to notice"

This reverts commit c34f904231f92b71c1e18d4fdd19a26a3b9d907d.
Revert "Messing with padding to test github stylesheets"

This reverts commit a68c3f8fbc28e2d18bef39c8ad7fc1706af1b0a8.