Point readme to correct docs for production builds (#153)

After an update to the docs, the production build was pointing to an outdated link. This commit directs the link to the appropriate location in the React docs.

Author: qstearns

README.md

@@ -248,7 +248,7 @@ See below for more info.
 
 **You might also see this error** if you’re calling a `PropTypes` validator from your own custom `PropTypes` validator. In this case, the fix is to make sure that you are passing *all* of the arguments to the inner function. There is a more in-depth explanation of how to fix it [on this page](https://facebook.github.io/react/warnings/dont-call-proptypes.html#fixing-the-false-positive-in-third-party-proptypes). Alternatively, you can temporarily keep using `React.PropTypes` until React 16, as it would still only warn in this case.
 
-If you use a bundler like Browserify or Webpack, don’t forget to [follow these instructions](https://facebook.github.io/react/docs/installation.html#development-and-production-versions) to correctly bundle your application in development or production mode. Otherwise you’ll ship unnecessary code to your users.
+If you use a bundler like Browserify or Webpack, don’t forget to [follow these instructions](https://reactjs.org/docs/optimizing-performance.html#use-the-production-build) to correctly bundle your application in development or production mode. Otherwise you’ll ship unnecessary code to your users.
 
 ## PropTypes.checkPropTypes