Filled in section 1.1 to describe the changes

csaf_2.0_errata_01/index.md

@@ -97,7 +97,9 @@ There are no changes to the published CSAF document. Changes have been made only
 
 ## 1.1 Description of changes
 
-Describe adding the "s" to "mirror" as you wish.
+In the aggregator schema, a typo has been corrected that blocked creation of any valid JSON aggregator document instance.
+
+In line 178 of the aggregator_json_schema.json the entry "mirror" as requireed field has beend corrected to be "mirrors" to match the existing type property definition in line 187 of the same schema file. 
 
 ## 1.2 Scope of changes