Update documentation for loop task (DO_WHILE) (#2965)

* update doc for loop task

* better language

docs/docs/reference-docs/do-while-task.md

@@ -14,14 +14,14 @@ When scheduled, each task of this loop will see its `taskReferenceName` concaten
 
 Each task output is stored as part of the DO_WHILE task, indexed by the iteration value (see example below), allowing the condition to reference the output of a task for a specific iteration (eg. $.LoopTask['iteration']['first_task'])
 
-The DO_WHILE task is set to `FAILED` as soon as one of the loopTask fails. In such case retry, iteration starts from 1.
+The DO_WHILE task is set to `FAILED` as soon as one of the loopOver fails. In such case retry, iteration starts from 1.
 
 #### Limitations 
 - Domain or isolation group execution is unsupported; - Nested DO_WHILE is unsupported; 
-- SUB_WORKFLOW is unsupported; 
-- Since loopover tasks will be executed in loop inside scope of parent do while task, crossing branching outside of DO_WHILE task is not respected. 
+- Since loopover tasks will be executed in loop inside scope of parent do while task, crossing branching outside of DO_WHILE task is not respected.
+- Nested DO_WHILE tasks are not supported. However, DO_WHILE task supports SUB_WORKFLOW as loopOver task, so we can achieve similar functionality.
 
-Branching inside loopover task is supported.
+Branching inside loopOver task is supported.