Drop in Javascript component - How to handle ‘configuration'

I’m trying to create a Javascript component that I can simply ‘include’ on a page and it basically outputs a form. I will probably use Handlebars templates within my component.

However, I’m struggling with how best to structure the configuration of my component I thought of some how passing it in like:

<script src = “my-component.js”>
    var config = {
        key1: ‘whatever’,
        key2: ‘whatever'
    }
</script>

...But how could I then get hold of my config object, within my-component.js?

Is there a more preferred approac