Add a when not to use case to forbid-foreign-prop-types

Author: lencioni

docs/rules/forbid-foreign-prop-types.md

@@ -28,3 +28,5 @@ import SomeComponent, {propTypes as someComponentPropTypes} from './SomeComponen
 ## When not to use
 
 This rule aims to make a certain production optimization, removing prop types, less prone to error. This rule may not be relevant to you if you do not wish to make use of this optimization.
+
+If you are writing a higher-order component that hoists the wrapped component's propTypes, you might want to disable this rule.