Add concrete example

[cge]

Hi, following the issue here https://github.com/ionic-team/stencil-ds-react-template/issues/3 I found some time again today and discovered there is React wrapper code in the Ionic code base already: https://github.com/ionic-team/ionic/tree/master/packages/react

I think it will be helpful for those having to use Stencil and React together to see a concrete working example. In this light, I took only the necessary bits from above to support wrapping the default stencil-component-starter MyComponent.

Names containing Ionic or ion where replaced by corresponding ones using Stencil. There are likely many folks who will use Stencil components outside of an Ionic context.

Please also see this related fix: https://github.com/ionic-team/stencil-component-starter/pull/83

Thanks!