index.html: added link to Bitcoin Magazine under "Resources"

Bitcoin Magazine is now a part of the Bitcoin community, with over 3,000 readers and growing daily, a 2-year exclusive contract for US distribution at Barnes & Noble, and acceptance into /r/Bitcoin as an official Bitcoin community subreddit. I ask that the bitcoin website embrace this magazine as it is already being used as a viable tool for explaining bitcoin to newbies, bringing more interest to bitcoin, and legitimizing it in a nationally distributed, Forbes and Time magazine quoted medium.

Thank you.