Declarative Stepper step property

[pmoleri]

Having React background, I expect the stepper step to be able to be changed in the template and not only through imperative API.
e.g.

html`
<igc-stepper step="${currentStep}">
    <igc-step>
       <div slot="indicator"></div>
       <p slot="title">Home</p>
       <p slot="subtitle">Home Sub Title</p>
       <div>
           <button @click="${setNextStep}">Next</button>
       </div
    </igc-step>
</igc-stepper>
`
setNextStep() {
    if (this.currentStep < 4) {
        this.currentStep++;
    }
}

@damyanpetev