typos (#24)

Author: kivvvvv

exercises/README.mdx

@@ -64,22 +64,22 @@ built with React:
       - Browser updates UI components
   - Browser requests data
     - Server generates data response
-      - Browser sends JSON
+      - Server sends JSON
         - Browser updates UI with JSON data
 
 - User triggers state change (i.e., route change)
 
   - Browser renders pending UI
   - Browser requests new data
     - Server generates data response
-      - Browser sends JSON
+      - Server sends JSON
         - Browser updates UI with JSON data
 
 - User triggers action (i.e., form submission)
   - Browser renders pending UI
   - Browser makes POST request
     - Server performs action with POST body
-      - Browser sends JSON
+      - Server sends JSON
         - Browser updates UI with JSON data
 
 </details>