Update README.mdx

Author: kentcdodds

exercises/README.mdx

@@ -14,7 +14,7 @@ application.
 The core of everything we'll be doing revolves around the
 [`Suspense`](https://react.dev/reference/react/Suspense) component and the
 [`use`](https://react.dev/reference/react/use) hook (we'll build our own
-version of this to really get how it works! The `Suspense` component
+version of this to really get how it works. The `Suspense` component
 enables you to declaratively tell React what to render while waiting for
 something to load. The `use` hook enables you to convert something async (a
 promise) into the resolved value.