fix minor spelling errors in docs (pytorch#140)

Author: brettkoonce

beginner_source/pytorch_with_examples.rst

@@ -207,7 +207,7 @@ Up to this point we have updated the weights of our models by manually
 mutating the ``.data`` member for Variables holding learnable
 parameters. This is not a huge burden for simple optimization algorithms
 like stochastic gradient descent, but in practice we often train neural
-networks using more sophisiticated optimizers like AdaGrad, RMSProp,
+networks using more sophisticated optimizers like AdaGrad, RMSProp,
 Adam, etc.
 
 The ``optim`` package in PyTorch abstracts the idea of an optimization

index.rst

@@ -110,7 +110,7 @@ Advanced Tutorials
 ------------------
 
 .. galleryitem:: advanced/neural_style_tutorial.py
-    :intro: This tutorial explains how to impletment the Neural-Style algorithm developed by Leon A. Gatys, Alexander S. Ecker and Matthias Bethge.
+    :intro: This tutorial explains how to implement the Neural-Style algorithm developed by Leon A. Gatys, Alexander S. Ecker and Matthias Bethge.
 
 .. galleryitem:: advanced/numpy_extensions_tutorial.py