By default, the page shows a simple example, e.g.:
But, as you can see in the Canvas example above, you can customize this example. To do so, just add an entry to your package.json.
"tonicExample": "var _ = require('underscore');"
You can also put the example in a separate file, if you prefer, and then add this property instead:
If you want to read more about the npm/tonic integration, check out this blog post.