testing utilities for the validity library; documentation

 Note: There are companion instance packages for this library:
  * genvalidity-aeson
  * genvalidity-bytestring
  * genvalidity-containers
  * genvalidity-path
  * genvalidity-scientific
  * genvalidity-text
  * genvalidity-time
  * genvalidity-unordered-containers
  * genvalidity-uuid
  * genvalidity-vector
 .
 This package provides the documentation for a library for the Haskell
 programming language.
 See http://www.haskell.org/ for more information on Haskell.