Update typings

[mkozhukharenko]

• add typings for linkTo addon
• action must return any since it brakes typings chain

So, having such example leads to the typescript error
error TS2322: Type 'Function' is not assignable to type '(newVal: string) => void'.

interface Props {
    onChange?(newVal: string): void,
}

class ExampleComponent extends Component<Props, void> {
    render() {
        return (
                <input onChange={this.props.onChange}>Hi!</div>
        )
    }
}

storiesOf('Example', module)
        .add('Regular use case', () => (
                <ExampleComponent onChange={action('changed')}/>
        ))

[arunoda]

Thanks.