1: Setup for sheet

Sheet.tsx

// ... imports

interface SheetProps {
  minHeight?: number;
  maxHeight?: number;
  expandedHeight?: number;
}

type SheetPositions = 'minimised' | 'maximised' | 'expanded';

const window = Dimensions.get('window');
const screen = Dimensions.get('screen');

const NAV_HEIGHT = 48;

// component will go here