adding prop-types in reactjs code example

Example 1: how to make proptypes either or

size: PropTypes.oneOfType([
  PropTypes.string,
  PropTypes.number
]),

Example 2: proptypes

Basic types:
- PropTypes.any: The prop can be of any data type
- PropTypes.bool: The prop should be a Boolean
- PropTypes.number: The prop should be a number
- PropTypes.string: The prop should be a string
- PropTypes.func: The prop should be a function
- PropTypes.array: The prop should be an array
- PropTypes.object: The prop should be an object
- PropTypes.symbol: The prop should be a symbol

Renderable types:
- PropTypes.node: The prop should be anything that can be rendered by React
  a number, string, element, or array (or fragment) containing these types
- PropTypes.element: The prop should be a React element

Instance types:
- PropTypes.instanceOf(class): The prop should be an instance of class

Multiple types:
- PropTypes.oneOf: The prop is limited to a specified set of values,
  treating it like an enum
- PropTypes.oneOfType: The prop should be one of a specified set of
  types, behaving like a union of types
  
Collection types:
- PropTypes.arrayOf: ensures that the prop is an array in which all 
  items match the specified type.
- PropTypes.objectOf: ensures that the prop is an object in which all 
  property values match the specified type.
- PropTypes.shape: ensures that the prop is an object that contains a set 
  of specified keys with values of the specified types.
- PropTypes.exact: use for strict (or exact) object matching