BevyRenet: update README

bevy_renet/README.md

@@ -7,3 +7,88 @@
 A Bevy Plugin for the [renet](https://github.com/lucaspoffo/renet) crate.
 A network crate for Server/Client with cryptographically secure authentication and encypted packets.
 Designed for fast paced competitive multiplayer games.
+
+## Usage
+Bevy renet is a small layer over the `renet` crate, it adds systems to call the client/server `update`and `send_packets`. `RenetClient` and `RenetServer` need to be added as a resource, so the setup is similar to `renet` itself:
+
+#### Server
+```rust
+let mut app = App::new();
+app.add_plugin(RenetServerPlugin);
+
+let server = RenetServer::new(...);
+app.insert_resource(server);
+
+app.add_system(send_message_system);
+app.add_system(receive_message_system);
+app.add_system(handle_events_system);
+
+// Systems
+
+fn send_message_system(mut server: ResMut<RenetServer>) {
+    let channel_id = 0;
+     // Send a text message for all clients
+    server.broadcast_message(channel_id, "server message".as_bytes().to_vec());
+}
+
+fn receive_message_system(mut server: ResMut<RenetServer>) {
+    let channel_id = 0;
+     // Send a text message for all clients
+    for client_id in server.clients_id().into_iter() {
+        while let Some(message) = server.receive_message(client_id, channel_id) {
+            // Handle received message
+        }
+    }
+}
+
+fn handle_events_system(mut server_events: EventReader<ServerEvent>) {
+    while let Some(event) = server.get_event() {
+    for event in server_events.iter() {
+        match event {
+            ServerEvent::ClientConnected(id, user_data) => {
+                println!("Client {} connected", id);
+            }
+            ServerEvent::ClientDisconnected(id) => {
+                println!("Client {} disconnected", id);
+            }
+        }
+    }
+}
+```
+
+#### Client
+```rust
+let mut app = App::new();
+app.add_plugin(RenetClientPlugin);
+
+let client = RenetClient::new(...);
+app.insert_resource(client);
+
+app.add_system(send_message_system);
+app.add_system(receive_message_system);
+
+// Systems
+
+fn send_message_system(mut client: ResMut<RenetClient>) {
+    let channel_id = 0;
+     // Send a text message to the server
+    client.send_message(channel_id, "server message".as_bytes().to_vec());
+}
+
+fn receive_message_system(mut client: ResMut<RenetClient>) {
+    let channel_id = 0;
+    while let Some(message) = client.receive_message(channel_id) {
+        // Handle received message
+    }
+}
+```
+
+## Example
+
+You can run the `simple` example with:
+* Server: `cargo run --example simple -- server`
+* Client: `cargo run --example simple -- client`
+
+If you want a more complex example you can checkout the [demo_bevy](https://github.com/lucaspoffo/renet/tree/master/demo_bevy) sample:
+
+[Bevy Demo.webm](https://user-images.githubusercontent.com/35241085/180664609-f8c969e0-d313-45c0-9c04-8a116896d0bd.webm)