Make the ProbabilisticScoringParameters field public to change it

There's no reason a user shouldn't be able to change the scoring
parameters at runtime between routing calls, so we let them do so
here by making the parameters field public.

lightning/src/routing/scoring.rs

@@ -365,7 +365,10 @@ pub type ProbabilisticScorer<G, L> = ProbabilisticScorerUsingTime::<G, L, Config
 /// This is not exported to bindings users generally all users should use the [`ProbabilisticScorer`] type alias.
 pub struct ProbabilisticScorerUsingTime<G: Deref<Target = NetworkGraph<L>>, L: Deref, T: Time>
 where L::Target: Logger {
-	params: ProbabilisticScoringParameters,
+	/// The parameters used when scoring channels for routing. These can be tweaked at runtime
+	/// between routing calls as necessary. Note that changing decay parameters may or may not
+	/// impact channels which were last scored prior to the new half-life.
+	pub params: ProbabilisticScoringParameters,
 	network_graph: G,
 	logger: L,
 	// TODO: Remove entries of closed channels.