Fix broken link for suspense demo (#2418)

content/blog/2018-11-27-react-16-roadmap.md

@@ -175,7 +175,7 @@ function App() {
 // provide Suspense integrations with similar APIs.
 ```
 
-There is no official documentation for how to fetch data with Suspense yet, but you can find some early information in [this talk](https://youtu.be/ByBPyMBTzM0?t=1312) and [this small demo](https://github.com/facebook/react/tree/master/fixtures/unstable-async/suspense). We'll write documentation for React Cache (and how to write your own Suspense-compatible library) closer to this React release, but if you're curious, you can find its very early source code [here](https://github.com/facebook/react/blob/master/packages/react-cache/src/ReactCache.js).
+There is no official documentation for how to fetch data with Suspense yet, but you can find some early information in [this talk](https://youtu.be/ByBPyMBTzM0?t=1312) and [this small demo](https://github.com/facebook/react/blob/master/packages/react-devtools/CHANGELOG.md#suspense-toggle). We'll write documentation for React Cache (and how to write your own Suspense-compatible library) closer to this React release, but if you're curious, you can find its very early source code [here](https://github.com/facebook/react/blob/master/packages/react-cache/src/ReactCache.js).
 
 The low-level Suspense mechanism (suspending rendering and showing a fallback) is expected to be stable even in React 16.6. We've used it for code splitting in production for months. However, the higher-level APIs for data fetching are very unstable. React Cache is rapidly changing, and will change at least a few more times. There are some low-level APIs that are [missing](https://github.com/reactjs/rfcs/pull/89) for a good higher-level API to be possible. We don't recommend using React Cache anywhere except very early experiments. Note that React Cache itself isn't strictly tied to React releases, but the current alphas lack basic features as cache invalidation, and you'll run into a wall very soon. We expect to have something usable with this React release.