[API Shield] update API Shield changelog (#17709)

* update API Shield changelog

* add custom rules link

* sept update

Author: patriciasantaana

src/content/changelogs/api-shield.yaml

@@ -5,6 +5,16 @@ productLink: "/api-shield/"
 productArea: Application security
 productAreaLink: /fundamentals/reference/changelog/security/
 entries:
+  - publish_date: "2024-10-18"
+    title: API Shield fields in Custom Rules
+    description: |-
+      Customers can now use API Shield product feature fields in [custom rules](/waf/custom-rules/), referencing features such as [JWT Validation](/api-shield/security/jwt-validation/), [session identifiers](/api-shield/get-started/#session-identifiers), and [Schema Validation](/api-shield/security/schema-validation/).
+
+  - publish_date: "2024-09-25"
+    title: Fallthrough rule for Schema Validation 2.0
+    description: |-
+      Customers can now enable the [Fallthrough Action](/api-shield/security/schema-validation/#add-validation-by-adding-a-fallthrough-rule) for Schema Validation 2.0 to block or log requests that do not match the endpoints listed in schemas protected by Schema Validation 2.0.
+
   - publish_date: "2024-08-28"
     title: Increased capacity for Endpoint Management and Schema Validation
     description: |-