Feature: Narrowing Rules and Step modifications

[rocky]

Especially in the early porting phase, it would be nice if we could specify loading section parts of the integration rules. For example, just the 1 integration rules, the 1.1-1.3 integration rules, the 2 integration rules, or the 1-2 integration rules, etc.

Similarly, it would be nice to add step tracing, but just to various sections.

[aravindh-krishnamoorthy]

Will be handled after #7