Updated README with yambo website
Updated README with yambo website

palful/yambopy,henriquemiranda/yambo-py,henriquemiranda/yambo-py,alexmoratalla/yambo-py,henriquemiranda/yambopy,alexandremorlet/yambopy,alexandremorlet/yambopy,palful/yambopy,alexmoratalla/yambopy,henriquemiranda/yambopy,alexmoratalla/yambopy,alexmoratalla/yambo-py