ATLAS-2719: Update documentation on classification propagation to include entity delete cases

docs/src/site/twiki/ClassificationPropagation.twiki

@@ -42,13 +42,35 @@ created view as well.
 <img src="images/twiki/classification-propagation-5.png"/>
 
 ---++ Delete an entity
+*Case 1:*
 When an entity is deleted, classifications associated with this entity will be removed from all entities the
 classifications are propagated to.
 
 For example. when _employees_ table is deleted, classifications associated with this table are removed from
 'employees_view' view.
 
-<img src="images/twiki/classification-propagation-6.png"/>
+<img src="images/twiki/classification-propagation-6.png" width="800" style="margin-left:20px"></img>
+
+*Case 2:*
+When an entity is deleted in the middle of a lineage path, the propagation link is broken and previously propagated
+classifications will be removed from all derived entities of the deleted entity.
+
+For example. when 'us_employees' table is deleted, classifications propagating through this table (*PII*) are removed from
+'ca_employees' table, since the only path of propagation is broken by entity deletion.
+
+<img src="images/twiki/classification-propagation-entity-delete-1.png" width="800" style="margin-left:20px"></img>
+
+<img src="images/twiki/classification-propagation-entity-delete-2.png" width="800" style="margin-left:20px"></img>
+
+*Case 3:*
+When an entity is deleted in the middle of a lineage path and if there exists alternate path for propagation, previously propagated classifications will be retained.
+
+For example. when 'us_employees' table is deleted, classifications  propagating (*PII*) through this table are retained in
+'ca_employees' table, since there are two propagation paths available and only one of them is broken by entity deletion.
+
+<img src="images/twiki/classification-propagation-entity-delete-3.png" width="800" style="margin-left:20px"></img>
+
+<img src="images/twiki/classification-propagation-entity-delete-4.png" width="800" style="margin-left:20px"></img>
 
 ---++ Control Propagation
 Apache Atlas provides few options to control whether/where a classification is propagated.