message: Updated README.md
  Edited the word 'lets you' to 'enables you to', which I think is better for this sentence. The word 'enable' here gives the readers a feeling that the architecture makes some awesome things possible, while 'let' is more like to give some permissions to the users.
diff: **TensorFlow** is an open source software library for numerical computation using
  data flow graphs. The graph nodes represent mathematical operations, while
  the graph edges represent the multidimensional data arrays (tensors) that flow
  -between them. This flexible architecture lets you deploy computation to one
  +between them. This flexible architecture enables you to deploy computation to one
  or more CPUs or GPUs in a desktop, server, or mobile device without rewriting
  code. TensorFlow also includes TensorBoard, a data visualization toolkit.
  