fix: mention the Ultimate requirement in the beginning (#4624)

Author: zamulla

docs/topics/kotlin-notebook-overview.md

@@ -3,6 +3,10 @@
 [Kotlin Notebook](https://plugins.jetbrains.com/plugin/16340-kotlin-notebook) is a dynamic plugin for IntelliJ IDEA that 
 provides an interactive environment to create and edit notebooks, leveraging the full potential of Kotlin's capabilities.
 
+> The Kotlin Notebook plugin requires IntelliJ IDEA Ultimate.
+> 
+{style="note"}
+
 Get ready for a seamless coding experience where you can develop and experiment with Kotlin code, receive immediate outputs, and integrate code, 
 visuals, and text within the IntelliJ IDEA ecosystem.