Simplify type aliasing somewhat around times

.. as the current C bindings generator isn't capable of handling
type aliases in generics in type alias definition currently.

Author: TheBlueMatt

lightning/src/routing/scoring.rs

@@ -306,12 +306,30 @@ impl ReadableArgs<u64> for FixedPenaltyScorer {
 }
 
 #[cfg(not(feature = "no-std"))]
-type ConfiguredTime = std::time::Instant;
-#[cfg(feature = "no-std")]
-use util::time::Eternity;
+/// [`Score`] implementation using channel success probability distributions.
+///
+/// Based on *Optimally Reliable & Cheap Payment Flows on the Lightning Network* by Rene Pickhardt
+/// and Stefan Richter [[1]]. Given the uncertainty of channel liquidity balances, probability
+/// distributions are defined based on knowledge learned from successful and unsuccessful attempts.
+/// Then the negative `log10` of the success probability is used to determine the cost of routing a
+/// specific HTLC amount through a channel.
+///
+/// Knowledge about channel liquidity balances takes the form of upper and lower bounds on the
+/// possible liquidity. Certainty of the bounds is decreased over time using a decay function. See
+/// [`ProbabilisticScoringParameters`] for details.
+///
+/// Since the scorer aims to learn the current channel liquidity balances, it works best for nodes
+/// with high payment volume or that actively probe the [`NetworkGraph`]. Nodes with low payment
+/// volume are more likely to experience failed payment paths, which would need to be retried.
+///
+/// # Note
+///
+/// Mixing the `no-std` feature between serialization and deserialization results in undefined
+/// behavior.
+///
+/// [1]: https://arxiv.org/abs/2107.05322
+pub type ProbabilisticScorer<G, L> = ProbabilisticScorerUsingTime::<G, L, std::time::Instant>;
 #[cfg(feature = "no-std")]
-type ConfiguredTime = Eternity;
-
 /// [`Score`] implementation using channel success probability distributions.
 ///
 /// Based on *Optimally Reliable & Cheap Payment Flows on the Lightning Network* by Rene Pickhardt
@@ -334,7 +352,7 @@ type ConfiguredTime = Eternity;
 /// behavior.
 ///
 /// [1]: https://arxiv.org/abs/2107.05322
-pub type ProbabilisticScorer<G, L> = ProbabilisticScorerUsingTime::<G, L, ConfiguredTime>;
+pub type ProbabilisticScorer<G, L> = ProbabilisticScorerUsingTime::<G, L, ::util::time::Eternity>;
 
 /// Probabilistic [`Score`] implementation.
 ///