Update Readme.md with Java versions

Author: nhirrle

Readme.md

@@ -62,6 +62,12 @@ AECU requires Java 8 and AEM 6.5 or AEM Cloud. For older AEM versions see below.
 | 6.5 (>=6.5.13)<br/>Cloud  | included | 6.x, 5.x   |
 | 6.5 (>=6.5.3 && < 6.5.13) | included | 6.0.1, 5.x |
 
+## Java 
+
+Java 8 is supported but may be dropped moving forward. 
+Please upgrade to at least Java 11.
+For Java 21 and AEM Cloud, please use AECU version >= 6.6.
+Java 17 for AEM 6.5 2025 requires AECU version >= 6.6.1.
 
 ## Older AEM versions
 For AEM 6.3/6.4 please see here what versions are compatible. Groovy Console can be installed manually if [bundle install](#bundleInstall) is not used.