DOC: Update compare_entities Docstring to describe which keys are used in the diff

src/linkahead/apiutils.py

@@ -196,6 +196,8 @@ def compare_entities(entity0: Optional[Entity] = None,
     that are missing in the other entity, and the 'properties' dict contains
     properties and SPECIAL_ATTRIBUTES if they are missing or different from
     their counterparts in the other entity.
+    The key used to represent a parent or property is the entities name if the
+    name is present for both compared entities, the id otherwise.
 
     The value of the properties dict for each listed property is again a dict
     detailing the differences between this property and its counterpart.
@@ -224,9 +226,9 @@ def compare_entities(entity0: Optional[Entity] = None,
 
     Params
     ------
-    entity0                : Entity
+    entity0:                    Entity
                                 First entity to be compared.
-    entity1                : Entity
+    entity1:                    Entity
                                 Second entity to be compared.
     compare_referenced_records: bool, default: False
                                 If set to True, values with referenced records