Update README.md

Author: tlambert03

README.md

@@ -27,7 +27,7 @@ basic color support, but they all either depend on matplotlib, provide a
 specialized set of colormaps intended to extend those provided by matplotlib, or
 roll their own colormap solution that vendors/duplicates other libraries.
 
-`cmap` is a lightweight, library that provides a large collection of colormaps
+`cmap` is a lightweight library that provides a large collection of colormaps
 with no dependencies beyond numpy.  It provides exports to a number of known
 third-party colormap objects, allowing it to be used across a wide range of
 python visualization libraries.  The intention is to provide a library that can