Update README.rst

Co-Authored-By: Andrew Murray <[email protected]>

Author: matthew-brett

README.rst

@@ -85,7 +85,7 @@ Build phase
 Specify the Manylinux version to build for with the `MB_ML_VER` environment variable.  The default version is `1`.  Versions that are currently valid are:
 
 * `1` (see [PEP 513](https://www.python.org/dev/peps/pep-0513);
-* `2010` (see PEP
+* `2010` (see [PEP
   571](https://www.python.org/dev/peps/pep-0571).
 
 At some point `2014` will be a valid version - see [PEP