Adds explanatory comments to DataWeave script

rollup/core/dw/jsonToRollupState.dwl

@@ -2,11 +2,14 @@
 input records application/json
 output application/apex
 
+// if the attributes property, which only exists on serialized SObjects, is present when trying to deserialize
+// it leads to the following error: System.DataWeaveScriptException: Error writing item: Invalid field "attributes" for type "{your SObject Type}"
 var getCompliantSObject = (item) -> item filterObject (value, key) -> (("" ++ key) != "attributes")
 ---
 // String coercion used to avoid errors like:
 // Invalid type: "org.mule.weave.v2.model.values.MaterializedAttributeDelegateValue"
 records map (record) -> "" ++ record.typeName match {
+                // regex here handles namespaced versions of the class name
                 case matches /(.*\.|)RollupState\.SObjectInfo/ -> {
                         key: record.key,
                         keyLength: record.keyLength,