f Add lightning-liquidtity as reference implementation

Author: tnull

blip-0051.md

@@ -13,6 +13,13 @@ The goal of this specification is to provide a standardized LSP API for wallets
 
 LSPS1 depends on the [LSPS0/bLIP 50](./blip-0050.md) and therefore [BOLT8](https://github.com/lightning/bolts/blob/master/08-transport.md) as a transport layer.
 
+## Reference Implementation
+
+A reference implementation of this protocol can be found as part of the
+[`lightning-liquidity`][] crate.
+
+[`lightning-liquidity`]: https://github.com/lightningdevkit/rust-lightning/tree/main/lightning-liquidity
+
 ## Definitions
 
 ### Data types