Add link to gufe from landing page (#20)

Author: atravitz

docs/index.rst

@@ -6,7 +6,7 @@
 AlchemicalNetwork Transformation Prioritization Library
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-The stratocaster library is complimentary to gufe and provides suggestions, via Strategies, for optimally executing Transformation Protocols defined in AlchemicalNetworks.
+The stratocaster library is complementary to `gufe <https://gufe.openfree.energy/>`_ and provides suggestions, via Strategies, for optimally executing Transformation Protocols defined in AlchemicalNetworks.
 
 This library includes a set of Strategy implementations as well as base classes to facilitate the creation of custom Strategy implementations.