Update the project page to v0.3.0

@3oheme in this closed issue #21 and I, have noticed that the Griddle project page always uses the first version of griddle (cf.: 8d7be688baff619cffef8b107fb996c877f54b77).

We can see the old push classes (in files) and the weird spacings between the grid's columns (on screen).

I thought it might be interesting to update normalize.css in the same time. I separated this change in two commits to leave you the choice to pick up what you want.

Xavier.