Add graphs back to about page

[davelab6]

@AndreasLarsen following #16 I suggest adding the graphs back into http://fontforge.github.io/en-US/downloads/ :)

[larsenwork]

I was actually thinking turning that page into a unified download page once we are sure the mac installer is working and then make homepage download bar link directly to the files (for win + mac at least) as per @adrientetar suggestion #40 (comment)

We could have a combined pie-chart on that page although I'm still not sure how relevant I think that information is :)

[davelab6]

I think its interesting to see how dominant Windows is... even better I suppose would be a graph of the split over time :) Maybe put at the end of the page instead of the top

[larsenwork]

Interesting for us - but for a random user just wanting to download?

I think it belongs more on an about page of some kind.

[larsenwork]

A graph would be cool though - there's lots of room on the about page ;) http://fontforge.github.io/en-US/about/

[davelab6]

Agree about page is fine