Fix JSX link in design principles section (#855)

content/docs/design-principles.md

@@ -145,7 +145,7 @@ In a massive codebase like Facebook, being able to search for uses of specific A
 
 Optimizing for search is also important because of our reliance on [codemods](https://www.youtube.com/watch?v=d0pOgY8__JM) to make breaking changes. We want it to be easy and safe to apply vast automated changes across the codebase, and unique verbose names help us achieve this. Similarly, distinctive names make it easy to write custom [lint rules](https://github.com/yannickcr/eslint-plugin-react) about using React without worrying about potential false positives.
 
-[JSX](/docs/displaying-data.html#jsx-syntax) plays a similar role. While it is not required with React, we use it extensively at Facebook both for aesthetic and pragmatic reasons.
+[JSX](/docs/introducing-jsx.html) plays a similar role. While it is not required with React, we use it extensively at Facebook both for aesthetic and pragmatic reasons.
 
 In our codebase, JSX provides an unambiguous hint to the tools that they are dealing with a React element tree. This makes it possible to add build-time optimizations such as [hoisting constant elements](http://babeljs.io/docs/plugins/transform-react-constant-elements/), safely lint and codemod internal component usage, and [include JSX source location](https://github.com/facebook/react/pull/6771) into the warnings.