Added exampleSetFlag to nonValidationKeyword (#435)

Co-authored-by: ShubhamRwt <[email protected]>

Author: ShubhamRwt

src/main/java/com/networknt/schema/JsonMetaSchema.java

@@ -117,7 +117,8 @@ public static JsonMetaSchema getInstance() {
                             new NonValidationKeyword("title"),
                             new NonValidationKeyword("description"),
                             new NonValidationKeyword("default"),
-                            new NonValidationKeyword("definitions")
+                            new NonValidationKeyword("definitions"),
+                            new NonValidationKeyword("exampleSetFlag")
                     ))
                     .build();
         }