Updates to index.html

Why? Because it turns out I had some unused and incorrectly used bits there.

Meta author wasn't being used as I expected, turns out copyright is what I meant. Author is for your Google+ ID with ?rel=author added after so Google can link you to the site.

Also added revisit-after which is good practice to add. Makes sure people get a new cache after 30 days...

Also, just rearranged the hierarchy of things a little.

Title, description, keywords, copyright.
Author, canonical.
Revisit.