NyFader.bottom constructor
      
      NyFader.bottom({})
     
    
NyFader from bottom to top
Implementation
NyFader.bottom(
    {super.key,
    required this.child,
    this.color = Colors.black,
    this.strength = 1,
    this.alignment = const [Alignment.topCenter, Alignment.bottomCenter]}) {
  assert(strength >= 1 && strength <= 5, 'strength must be between 1 and 5');
  assert(alignment.length == 2,
      'alignment must be a list of 2 AlignmentGeometry objects');
}