Add missing period to React v18.0 blog post (#6842)

Author: jackspiva

src/content/blog/2022/03/29/react-v18.md

@@ -240,7 +240,7 @@ With Strict Mode in React 18, React will simulate unmounting and remounting the
 
 #### useTransition {/*usetransition*/}
 
-`useTransition` and `startTransition` let you mark some state updates as not urgent. Other state updates are considered urgent by default. React will allow urgent state updates (for example, updating a text input) to interrupt non-urgent state updates (for example, rendering a list of search results). [See docs here](/reference/react/useTransition)
+`useTransition` and `startTransition` let you mark some state updates as not urgent. Other state updates are considered urgent by default. React will allow urgent state updates (for example, updating a text input) to interrupt non-urgent state updates (for example, rendering a list of search results). [See docs here](/reference/react/useTransition).
 
 #### useDeferredValue {/*usedeferredvalue*/}