Fixed broken 'Contact Us' link

The very first link on this page is broken.

old: http://openhatch.readthedocs.org/en/latest/contributor/contact.html
new: http://openhatch.readthedocs.org/en/latest/community/contact.html

I have verified the that the new link is correct and working as intended.
Fixed 973 Enabled responsive design on all OH pages.

Responsive design is now here on the donate, training, events, homepage,
profile, projects pages.

I also fixed broken css selector img#volunteer-opportunities in search.css.