update readme

Author: AlemTuzlak

exercises/README.mdx

@@ -8,8 +8,7 @@ include the following topics:
 - 🔄 Routing
 - ⚡️ Defining custom links (including React 19 features)
 - 📦 Meta data and SEO practices (including React 19 features)
-- 📚 Server Data fetching
-- 🔒 Client Data fetching
+- 📚 Server Data fetching 
 - 🎉 Accessing and displaying data
 
 We will be building a full-stack application that demonstrates these concepts in action.