Change the WASM example to use rustpython from npm

wasm/example/package.json

@@ -1,10 +1,8 @@
 {
     "name": "rustpython-wasm-example",
     "version": "1.0.0",
-    "//1": "`dependencies.rustpython_wasm` would be the version of the npm",
-    "//2": "library in a real app",
     "dependencies": {
-        "rustpython_wasm": "file:../lib/pkg/"
+        "rustpython_wasm": "0.1.0-pre-alpha.1"
     },
     "devDependencies": {
         "raw-loader": "1.0.0",
@@ -12,7 +10,8 @@
         "webpack-cli": "^3.1.2"
     },
     "scripts": {
-        "build": "webpack"
+        "build": "webpack",
+        "dist": "webpack --mode production"
     },
     "license": "MIT"
 }