Website overhauled!

Thanks to barton26, peppernrino & everyone in the slack web-dev channel for helping create the latest version of the gridcoin website.

Do note that the above image was spliced together through multiple screenshots, it's best viewed directly.

Change log:

• Migrated from grctest repo to gridcoin-community repo (better organization & less centralization).
• New logo & colour scheme used throughout the website.
• Solo/Pool/Investor mode advantage/disadvantage section summarized in table format. This is far simpler and less wall-of-text-y.
• New download links for Mac OS (Thanks acey!)
• Boinc server docker repo added under 'other' downloads.
• Header and footer contents updated.
• Blog added.
• Contact us page added.
• Door.One added to exchanges header/footer (we'll have compatibility through open.grc).

Have any further suggestions or want to help development?

Please head on over to the gridcoin-site community repo on github & get submitting issues and or pull requests!