issue-4: updated README
issue-4: updated README

GraphKit/GraphKit-swift,GraphKit/GraphKit,GraphKit/GraphKit-swift,adamdahan/GraphKit,CosmicMind/GraphKit,adamdahan/GraphKit,CosmicMind/GraphKit,GraphKit/GraphKit,CosmicMind/Graph,NinjaIshere/GKGraphKit,CosmicMind/Graph,GraphKit/swift,GraphKit/swift