Document breaking changes

ChangeLog

@@ -71,6 +71,13 @@ the generation of reproducible random numbers in the presence of MPI parallelism
 and leads to cleaner code overall. Please see the documentation of
 `nifty6.random` for details.
 
+Interface Change for from_random and OuterProduct
+=================================================
+
+The sugar.from_random, Field.from_random, MultiField.from_random now take domain
+as the first argument and default to 'normal' for the second argument.
+Likewise OuterProduct takes domain as the first argument and a field as the second.
+
 Interface Change for non-linear Operators
 =========================================