Add Makefile and format rust core

Makefile

@@ -0,0 +1,5 @@
+rust_build:
+	cd rust && cargo build
+
+rust_fmt:
+	cd rust && cargo fmt

rust/src/player/server_node.rs

@@ -103,7 +103,11 @@ impl PlayerServerNode {
             Some(map) => map,
             None => return,
         };
-        let args = &[casted_bullet_node.to_variant(), 10.to_variant(), 10.to_variant()];
+        let args = &[
+            casted_bullet_node.to_variant(),
+            10.to_variant(),
+            10.to_variant(),
+        ];
         map.call("spawn_bullet", args);
     }
 }