Updated Server setup (markdown)

Server-setup.md

@@ -27,4 +27,80 @@ _Please check the [instances](https://github.com/Minestom/Minestom/wiki/Instance
 player.addEventCallback(PlayerLoginEvent.class, event -> {
    event.setSpawningInstance(YOUR_SPAWNING_INSTANCE);
 });
+```
+
+Here is an example of a working Minestom server
+```java
+package your.package;
+
+import net.minestom.server.MinecraftServer;
+import net.minestom.server.event.player.PlayerLoginEvent;
+import net.minestom.server.event.player.PlayerSpawnEvent;
+import net.minestom.server.instance.*;
+import net.minestom.server.instance.batch.ChunkBatch;
+import net.minestom.server.instance.block.Block;
+import net.minestom.server.network.ConnectionManager;
+import net.minestom.server.utils.Position;
+
+import java.util.Arrays;
+import java.util.List;
+
+public class MainDemo {
+
+    public static void main(String[] args) {
+        // Initialization
+        MinecraftServer minecraftServer = MinecraftServer.init();
+
+        InstanceManager instanceManager = MinecraftServer.getInstanceManager();
+        // Create the instance
+        InstanceContainer instanceContainer = instanceManager.createInstanceContainer();
+        // Set the ChunkGenerator
+        instanceContainer.setChunkGenerator(new GeneratorDemo());
+        // Enable the auto chunk loading (when players come close)
+        instanceContainer.enableAutoChunkLoad(true);
+
+        // Add event listeners
+        ConnectionManager connectionManager = MinecraftServer.getConnectionManager();
+        connectionManager.addPlayerInitialization(player -> {
+            // Set the spawning instance
+            player.addEventCallback(PlayerLoginEvent.class, event -> {
+                event.setSpawningInstance(instanceContainer);
+            });
+
+            // Teleport the player at spawn
+            player.addEventCallback(PlayerSpawnEvent.class, event -> {
+                player.teleport(new Position(0, 45, 0));
+            });
+        });
+
+        // Start the server
+        minecraftServer.start("localhost", 55555);
+    }
+
+    public static class GeneratorDemo extends ChunkGenerator {
+
+        @Override
+        public void generateChunkData(ChunkBatch batch, int chunkX, int chunkZ) {
+            // Set chunk blocks
+            for (byte x = 0; x < Chunk.CHUNK_SIZE_X; x++)
+                for (byte z = 0; z < Chunk.CHUNK_SIZE_Z; z++) {
+                    for (byte y = 0; y < 40; y++) {
+                        batch.setBlock(x, y, z, Block.STONE);
+                    }
+                }
+        }
+
+        @Override
+        public void fillBiomes(Biome[] biomes, int chunkX, int chunkZ) {
+            Arrays.fill(biomes, Biome.PLAINS);
+        }
+
+        @Override
+        public List<ChunkPopulator> getPopulators() {
+            return null;
+        }
+    }
+
+}
+
 ```