data () {
    const initializeState = () => {
      if (this.allowMultiple) {
        return this.defaultIndex || []
      } else {
        return this.defaultIndex || 0
      }
    }
    return {
      expandedIndex: initializeState()
    }
  }
CAccordion component

The wrapper that clones it's children
to pass it's prop to the `CAccordionItem`.

@extends CBox
@see Docs https://vue.chakra-ui.com/accordion