include LSPS5 on lightning-liquidity README

Author: martinsaposnic

lightning-liquidity/README.md

@@ -14,11 +14,15 @@ inbound Lightning liquidity for which they are willing and able to pay in bitcoi
   on-boarding of clients as the channel opening fees are deducted from the
   incoming payment, i.e., no funds are required client-side to initiate this
   flow.
+- [bLIP-55 / LSPS5] lets a client register HTTPS webhooks with its LSP so the LSP can send signed push 
+  notifications (for example "payment incoming") that wake the app when it is offline, which is essential 
+  for mobile wallets that get suspended in the background.
 
-To get started, you'll want to setup a `LiquidityManager` and configure it to be the `CustomMessageHandler` of your LDK node. You can then call `LiquidityManager::lsps1_client_handler` / `LiquidityManager::lsps2_client_handler`, or `LiquidityManager::lsps2_service_handler`, to access the respective client-side or service-side handlers.
+To get started, you'll want to setup a `LiquidityManager` and configure it to be the `CustomMessageHandler` of your LDK node. You can then call `LiquidityManager::lsps1_client_handler` / `LiquidityManager::lsps2_client_handler`, `LiquidityManager::lsps2_service_handler`, `LiquidityManager::lsps5_service_handler` or `LiquidityManager::lsps5_client_handler` to access the respective client-side or service-side handlers.
 
 `LiquidityManager` uses an eventing system to notify the user about important updates to the protocol flow. To this end, you will need to handle events emitted via one of the event handling methods provided by `LiquidityManager`, e.g., `LiquidityManager::next_event`.
 
 [bLIP-50 / LSPS0]: https://github.com/lightning/blips/blob/master/blip-0050.md
 [bLIP-51 / LSPS1]: https://github.com/lightning/blips/blob/master/blip-0051.md
 [bLIP-52 / LSPS2]: https://github.com/lightning/blips/blob/master/blip-0052.md
+[bLIP-55 / LSPS5]: https://github.com/lightning/blips/blob/master/blip-0055.md