feat: install moo and use in toy example

I failed to find a satisfactory way to compile and import moo.js with
   fixed specifiers, so finally I just gave up and patched the distributed
   code to be an es6 module. A bit ugly but it works.

etc/testscript.html

@@ -5,8 +5,8 @@
     <title>vrml1to97 test</title>
     <script>
       (async () => {
-        const vrml1to97 = await import('../dist/index.js')
-        console.log(vrml1to97.convert('test'))
+        const vrml1to97 = await import('../dist/vrml1to97/index.js')
+        console.log(vrml1to97.convert('if (moo) cows // hurray'))
       })()
     </script>
   </head>