Merge pull request #4274 from tankyleo/25-12-02-splicing-docs

Clarify splicing feature flag requirements

Author: TheBlueMatt

lightning/src/ln/channelmanager.rs

@@ -4858,6 +4858,12 @@ where
 	/// the channel. This will spend the channel's funding transaction output, effectively replacing
 	/// it with a new one.
 	///
+	/// # Required Feature Flags
+	///
+	/// Initiating a splice requires that the channel counterparty supports splicing. Any
+	/// channel (no matter the type) can be spliced, as long as the counterparty is currently
+	/// connected.
+	///
 	/// # Arguments
 	///
 	/// Provide a `contribution` to determine if value is spliced in or out. The splice initiator is