Update hello_input_system.adoc

Added new line breaks to table.

src/docs/asciidoc/jme3/beginner/hello_input_system.adoc

@@ -297,14 +297,17 @@ a| KeyTrigger(KeyInput.KEY_X)
 a| KeyTrigger(KeyInput.KEY_SPACE) 
 
 a| Keyboard: Return, Enter 
-<a| KeyTrigger(KeyInput.KEY_RETURN), KeyTrigger(KeyInput.KEY_NUMPADENTER)  
+<a| KeyTrigger(KeyInput.KEY_RETURN), +
+KeyTrigger(KeyInput.KEY_NUMPADENTER)  
 
 a| Keyboard: Escape 
 a| KeyTrigger(KeyInput.KEY_ESCAPE) 
 
 a| Keyboard: Arrows 
-a| KeyTrigger(KeyInput.KEY_UP), KeyTrigger(KeyInput.KEY_DOWN) +
-KeyTrigger(KeyInput.KEY_LEFT), KeyTrigger(KeyInput.KEY_RIGHT) 
+a| KeyTrigger(KeyInput.KEY_UP), +
+KeyTrigger(KeyInput.KEY_DOWN) +
+KeyTrigger(KeyInput.KEY_LEFT), +
+KeyTrigger(KeyInput.KEY_RIGHT) 
 
 |===