Update jsr223.md (#2155)

* Update jsr223.md

Add example of how to implement sharedCache in DSL rules.

Thanks to rlkoshak.

Signed-off-by: Udo Hartmann <udo1toni@users.noreply.github.com>

* Update jsr223.md

removed one empty line

---------

Signed-off-by: Udo Hartmann <udo1toni@users.noreply.github.com>
Co-authored-by: stefan-hoehn <mail@stefanhoehn.com>

configuration/jsr223.md

@@ -402,6 +402,16 @@ sharedCache.remove("x")
 
 :::
 
+::: tab DSL
+
+```java
+sharedCache.put('foo', 'bar')
+sharedCache.get('foo') // returns null if doesn't exist
+shareCache.put('foo', null) // deletes the entry
+```
+
+:::
+
 ::: tab Jython
 
 ```python