Link to the tutorial from README header

Author: fitzgen

README.md

@@ -9,7 +9,7 @@
   </p>
 
   <h3>
-    <a href="#-usage">Usage</a>
+    <a href="https://rustwasm.github.io/docs/wasm-pack/tutorials/npm-browser-packages/index.html">Tutorial</a>
     <span> | </span>
     <a href="https://discordapp.com/channels/442252698964721669/443151097398296587">Chat</a>
   </h3>