Recommmended PureComponent instead of shallowCompare

Author: ishankbahl

content/docs/addons.md

@@ -22,7 +22,7 @@ The add-ons below are in the development (unminified) version of React only:
 The add-ons below are considered legacy and their use is discouraged. They will keep working in observable future, but there is no further development.
 
 - [`PureRenderMixin`](pure-render-mixin.html). Use [`React.PureComponent`](/docs/react-api.html#react.purecomponent) instead.
-- [`shallowCompare`](shallow-compare.html), a helper function that performs a shallow comparison for props and state in a component to decide if a component should update.
+- [`shallowCompare`](shallow-compare.html), a helper function that performs a shallow comparison for props and state in a component to decide if a component should update. Use [`React.PureComponent`](/docs/react-api.html#react.purecomponent) instead.
 - [`update`](update.html). Use [`kolodny/immutability-helper`](https://github.com/kolodny/immutability-helper) instead.
 - [`ReactDOMFactories`](dom-factories.html), pre-configured DOM factories to make React easier to use without JSX.