feat: link to rest api filters in relevant sections of the docs

Link to the REST API filters documentation from
doc pages where gRPC interceptors as mentioned
as well since interceptors and filters perform
the same functionality for the REST and gRPC
parts of the Zeebe Gateway.

docs/components/zeebe/technical-concepts/protocols.md

@@ -39,5 +39,5 @@ If there is no client in your target language yet, you can [build your own clien
 
 ## Intercepting calls
 
-Zeebe supports [loading arbitrary gRPC server interceptors](self-managed/zeebe-deployment/zeebe-gateway/interceptors.md) to intercept incoming
-calls.
+Zeebe supports loading arbitrary [gRPC server interceptors](self-managed/zeebe-deployment/zeebe-gateway/interceptors.md)
+and [Jakarta servlet filters](self-managed/zeebe-deployment/zeebe-gateway/filters.md) to intercept incoming calls.

docs/guides/migrating-from-camunda-7/migration-readiness.md

@@ -97,8 +97,12 @@ We also recommend reviewing [BPMN elements supported in Camunda 8](/components/m
 - [Tasklist API](/apis-tools/tasklist-api-rest/tasklist-api-rest-overview.md)
 - [Operate API](/apis-tools/operate-api/overview.md) including historical info on processes
 - [Exporters](/self-managed/zeebe-deployment/exporters/exporters.md)
-- Client interceptors
-- [Gateway interceptors](/self-managed/zeebe-deployment/zeebe-gateway/interceptors.md)
+- Client middleware
+  - gRPC ClientInterceptors
+  - REST API middleware (client implementation dependent)
+- Gateway middleware
+  - [gRPC ServerInterceptors](/self-managed/zeebe-deployment/zeebe-gateway/interceptors.md)
+  - REST API [Jakarta Servlet Filters](/self-managed/zeebe-deployment/zeebe-gateway/filters.md)
 - [Job workers](/components/concepts/job-workers.md) on user tasks
 - [Job workers](/components/concepts/job-workers.md) on service tasks