limits update

Exercise-Configuration.md

@@ -312,12 +312,14 @@ Example:
 
 ## Limits
 
+Limits are applied to whole test, that means if there are multiple execution tasks, all are going to have these same limits. Limits has to be specified in a way it contains at least one time limit and also memory limit.
+
 Mandatory items are bold, optional italic, description of items follows:
 
 * **${test identification}** - identifier of test from database
     * _wall-time_ - elapsed real-time in seconds, defined as float
     * _cpu-time_ - elapsed cpu-time in seconds, defined as float
-    * _memory_ - maximal memory usage in kilobytes
+    * **memory** - maximal memory usage in kilobytes
     * _parallel_ - maximal number of threads/processes used
 
 Example: