Fix docstrings and remove unnecessary GDPData method

Author: pulsipher

docs/src/api.md

@@ -2,5 +2,5 @@
 
 ```@autodocs
 Modules = [DisjunctiveProgramming]
-Order   = [:type, :function]
+Order   = [:macro, :function, :type]
 ```

src/datatypes.jl

@@ -422,7 +422,4 @@ mutable struct GDPData
             false,
             )
     end
-    function GDPData(args...)
-        new(args...)
-    end
 end