Metergroup: container should be named: meters

[Johardmeier]

I am not sure enough to make a pullrequest, but I think in metergroup.js: the metercontainer section should be just meters:

` root: ({ props }) => ({ class: [ // Flexbox 'flex gap-4',

        { 'flex-col': props.orientation == 'horizontal', 'flex-row': props.orientation == 'vertical' }
    ]
}),
meters: ({ props }) => ({...

`