Update README.adoc

Author: sdeleuze

README.adoc

@@ -1,5 +1,5 @@
 :spring_version: current
-:spring_boot_version: 2.4.3
+:spring_boot_version: current
 :Controller: https://docs.spring.io/spring/docs/{spring_version}/javadoc-api/org/springframework/stereotype/Controller.html
 :DispatcherServlet: https://docs.spring.io/spring/docs/{spring_version}/javadoc-api/org/springframework/web/servlet/DispatcherServlet.html
 :SpringApplication: https://docs.spring.io/spring-boot/docs/{spring_boot_version}/api/org/springframework/boot/SpringApplication.html
@@ -24,15 +24,14 @@ populating the `id` and `content` form fields. A results page will be displayed
 
 == What You Need
 
-:java_version: 11
 include::https://raw.githubusercontent.com/spring-guides/getting-started-macros/main/prereq_editor_jdk_buildtools.adoc[]
 
 include::https://raw.githubusercontent.com/spring-guides/getting-started-macros/main/how_to_complete_this_guide.adoc[]
 
 [[scratch]]
 == Starting with Spring Initializr
 
-You can use this https://start.spring.io/#!type=maven-project&language=java&platformVersion=2.5.5&packaging=jar&jvmVersion=11&groupId=com.example&artifactId=handling-form-submission&name=handling-form-submission&description=Demo%20project%20for%20Spring%20Boot&packageName=com.example.handling-form-submission&dependencies=web,thymeleaf[pre-initialized project] and click Generate to download a ZIP file. This project is configured to fit the examples in this tutorial.
+You can use this https://start.spring.io/#!type=maven-project&groupId=com.example&artifactId=handling-form-submission&name=handling-form-submission&description=Demo%20project%20for%20Spring%20Boot&packageName=com.example.handling-form-submission&dependencies=web,thymeleaf[pre-initialized project] and click Generate to download a ZIP file. This project is configured to fit the examples in this tutorial.
 
 To manually initialize the project: