add reference link

Author: codomposer

machine_learning/t_stochastic_neighbour_embedding.py

@@ -10,6 +10,7 @@
 Reference:
     van der Maaten, L., & Hinton, G. (2008). Visualizing data using t-SNE.
     Journal of Machine Learning Research, 9(86), 2579-2605.
+    https://lvdmaaten.github.io/tsne/
 
 For more details, see:
 https://en.wikipedia.org/wiki/T-distributed_stochastic_neighbor_embedding