Fix punctuation (numpy#281)

Author: InessaPawson

config.yaml

@@ -59,17 +59,17 @@ params:
   keyfeatures:
     features:
     - title: Powerful N-dimensional arrays
-      text:  Fast and versatile, the NumPy vectorization, indexing and broadcasting concepts are the de-facto standards of array computing today.
+      text:  Fast and versatile, the NumPy vectorization, indexing, and broadcasting concepts are the de-facto standards of array computing today.
     - title: Numerical computing tools
-      text: NumPy offers comprehensive mathematical functions, random number generators, linear algebra routines, Fourier transforms and more.
+      text: NumPy offers comprehensive mathematical functions, random number generators, linear algebra routines, Fourier transforms, and more.
     - title: Interoperable
-      text: NumPy supports a wide range of hardware and computing platforms, and plays well with distributed, GPU and sparse array libraries.
+      text: NumPy supports a wide range of hardware and computing platforms, and plays well with distributed, GPU, and sparse array libraries.
     - title: Performant
       text: The core of NumPy is well-optimized C code. Enjoy the flexibility of Python with the speed of compiled code.
     - title: Easy to use
-      text: NumPy's high level syntax makes it accessible to and productive for programmers from any background or experience level.
+      text: NumPy's high level syntax makes it accessible and productive for programmers from any background or experience level.
     - title: Open source
-      text: Distributed under a liberal [BSD license](https://github.com/numpy/numpy/blob/master/LICENSE.txt), NumPy is developed and maintained [publicly on GitHub](https://github.com/numpy/numpy) by a vibrant, responsive and diverse [community](/community).
+      text: Distributed under a liberal [BSD license](https://github.com/numpy/numpy/blob/master/LICENSE.txt), NumPy is developed and maintained [publicly on GitHub](https://github.com/numpy/numpy) by a vibrant, responsive, and diverse [community](/community).
   tabs:
     title: ECOSYSTEM
   section5: false