Adds setting up a PeerManager page

Author: Conor Okus

docs/.vuepress/config.js

@@ -95,7 +95,8 @@ const tutorialSidebar = [
         collapsable: false,
         children: [
           ['/tutorials/building-a-node-with-ldk/introduction', 'Introduction'],
-          ['/tutorials/building-a-node-with-ldk/setting-up-a-channel-manager', 'Setting up a Channel Manager']
+          ['/tutorials/building-a-node-with-ldk/setting-up-a-channel-manager', 'Setting up a Channel Manager'],
+          ['/tutorials/building-a-node-with-ldk/setting-up-a-peer-manager', 'Setting up a Peer Manager']
         ]
       },
     ],

docs/tutorials/building-a-node-with-ldk/setting-up-a-channel-manager.md

@@ -993,8 +993,6 @@ Otherwise, you can use LDK's `Confirm` interface as in the examples above. The h
 
 **What it's used for:** generating routes to send payments over
 
-**Example:** initializing `P2PGossipSync`
-
 <CodeSwitcher :languages="{rust:'Rust', java:'Java', kotlin:'Kotlin'}">
 
 <template v-slot:rust>

docs/tutorials/building-a-node-with-ldk/setting-up-a-peer-manager.md

@@ -0,0 +1,61 @@
+# Setting up a PeerManager
+
+The Peer Manager is responsible for managing a set of peer connections and all data associated with those peers.
+
+
+## Adding a PeerManager
+
+To add a PeerManager to your application, run:
+
+<CodeSwitcher :languages="{rust:'Rust', java:'Java', kotlin:'Kotlin'}">
+  <template v-slot:rust>
+
+  ```rust
+  use lightning::ln::peer_handler::{PeerManager};
+
+  let mut ephemeral_bytes = [0; 32];
+  rand::thread_rng().fill_bytes(&mut ephemeral_bytes);
+
+  let lightning_msg_handler = MessageHandler {
+    chan_handler: &channel_manager,
+    route_handler: &gossip_sync,
+  };
+
+  let ignoring_custom_msg_handler = IgnoringMessageHandler {};
+  let peer_manager = PeerManager::new(
+      lightning_msg_handler,
+      keys_manager.get_node_secret(),
+      &ephemeral_bytes,
+      &logger,
+      &ignoring_custom_msg_handler,
+  );
+  ```
+  </template>
+
+  <template v-slot:java>
+ 
+  ```java
+  import org.ldk.structs.PeerManager
+
+  PeerManager peerManager = channelManagerConstructor.peer_manager;
+  ```
+
+  </template>
+
+   <template v-slot:kotlin>
+ 
+  ```kotlin
+  import org.ldk.structs.PeerManager
+  
+  val peerManager: PeerManager = channelManagerConstructor.peer_manager;
+  ```
+
+  </template>
+</CodeSwitcher>
+
+**Implementation notes:** if you did not initialize `P2PGossipSync` in the previous step, you can initialize your own struct (which can be a dummy struct) that implements `RoutingMessageHandler`
+
+**Dependencies:** `ChannelManager`, `RoutingMessageHandler`, `KeysManager`, random bytes, `Logger`
+
+**References:** [Rust `PeerManager` docs](https://docs.rs/lightning/*/lightning/ln/peer_handler/struct.PeerManager.html), [Rust `RoutingMessageHandler` docs](https://docs.rs/lightning/*/lightning/ln/msgs/trait.RoutingMessageHandler.html), [Java `PeerManager` docs](https://github.com/lightningdevkit/ldk-garbagecollected/blob/main/src/main/java/org/ldk/structs/PeerManager.java), [Java `RoutingMessageHandler` docs](https://github.com/lightningdevkit/ldk-garbagecollected/blob/main/src/main/java/org/ldk/structs/RoutingMessageHandler.java)
+