Build examples again

This commit rebuilds all the examples. And adds a script that can build
them all.

usage:

```sh
node ./build-examples.js
```

build-examples.js

@@ -0,0 +1,40 @@
+const rollup = require('rollup');
+const resolve = require('rollup-plugin-node-resolve');
+const commonjs = require('rollup-plugin-commonjs');
+
+const fs = require('fs');
+const path = require('path');
+
+async function build(example) {
+  console.log('Building ' + example);
+
+  const inputOptions = {
+    input: path.resolve(`./examples/${example}/script.js`),
+    plugins: [
+      resolve(),
+      commonjs()
+    ]
+  }
+  const outputOptions = {
+    format: 'iife',
+    file: path.resolve(`./examples/${example}/build.js`),
+    name: example.replace(/-/g, ''),
+  }
+  // create a bundle
+  const bundle = await rollup.rollup(inputOptions);
+
+  // write bundle
+  await bundle.write(outputOptions);
+
+  console.log('Built ' + example);
+}
+
+const examples = fs.readdirSync('./examples');
+
+Promise.all(examples.map(build))
+  .then(()=> console.log('Success!'))
+  .catch(err => {
+    console.error('Failed!');
+    console.error(err);
+    process.exit(1);
+  });