feat: start to implement node_registry

nodes/multiply/src/lib.rs

@@ -5,6 +5,5 @@ pub extern "C" fn execute(a: u32, b: u32) -> u32 {
 
 #[no_mangle]
 pub extern "C" fn get_definition() -> String {
-    let bytes = include_str!("./node.json");
-    bytes.to_string()
+    include_str!("./node.json").to_string()
 }