Clarify §1.2.1: Constraint merging uses intersection semantics

[crowecawcaw]

Section 1.2.1 states:

These constraints do not need to be identical in every Job Parameter Definition for the same parameter name, but each constraint must become more constrained as a subsequent
definition is merged with the previous ones in processing order

The phrase "must become more constrained" is ambiguous. It could be read as requiring each definition to have stricter constraints than the previous, which would make wider constraints
an error.

The intended behavior is intersection semantics: the effective constraint is the most restrictive combination of all definitions. A wider constraint in a later definition is allowed but
has no effect.

Possible rewording:

These constraints do not need to be identical in every Job Parameter Definition for the same parameter name. The effective constraint for each property is the most
restrictive combination of all definitions. For example, if one definition has minLength: 3 and another has minLength: 5, the effective minimum length is 5.