added hello-world wasm example and npmPackage nix derivation

src/lib.rs

@@ -3,6 +3,8 @@
 
 static PROTO_VERSION: u8 = 1;
 
+// the core part houses the code that can run on any platform
+/*
 pub mod core {
     pub mod memstore;
     pub mod instance;
@@ -14,7 +16,12 @@ pub mod core {
 }
 
 pub use core::*;
-
+// */
+
+pub mod platform {
+    #[cfg(feature = "wasm-target")]
+    pub mod wasm;
+}