Update index.html

Included a missing charset, also removed header tags from sections. When there is only one title, it may be too redundant to reuse header tags when you already have an h tag (which means header) Scan this article for more details.

http://html5doctor.com/avoiding-common-html5-mistakes/

Also removed the footer. The content inside seemed like another section rather than a footer. A good use for a footer would be a copyright or something like that. Check mdn for more information.