Update README.md

README Update:

*Requirement to open the application and troubleshot

Author: MarceloV27

README.md

@@ -1,2 +1,8 @@
 I use JavaFX with IntelliJ Ultimate 
 Project User register 
+
+To open the application need to install 21 JDK link:
+https://www.oracle.com/java/technologies/downloads/?er=221886#java11-windows
+
+if you can not open the application check uninstall JDK are you use it and then install 21 JDK and open the application. 
+