• 전역에서 사용가능한 버튼 추가
• ButtonDefault, ButtonFlat

type ButtonDefaultProps = {
  content: string;
  iconSource?: ImageSourcePropType;
  height?: number;
  width?: number;
  borderRadius?: number;
  fontSize?: number;
};

  content,
  iconSource,
  height = 40,
  width = 100,
  borderRadius = 25,
  fontSize = 16,

type ButtonFlatProps = {
  content: string;
  color?: string;
  height?: number;
  width?: number;
  borderRadius?: number;
  shadowDisplay?: boolean;
  fontSize?: number;
};

  content,
  color,
  height = 40,
  width = 100,
  borderRadius = 12,
  shadowDisplay = true,
  fontSize = 16,