Update transport-encryption.md (#5832)

Fix: #5823
In the doc linked below,
https://knative.dev/docs/eventing/experimental-features/transport-encryption/#prerequisites

Eventing installation should be linked to https://knative.dev/docs/install/

Co-authored-by: Yan Song Liu <lysliu@cn.ibm.com>

docs/eventing/experimental-features/transport-encryption.md

@@ -24,7 +24,7 @@ Event producers are be able to connect to HTTPS endpoints with cluster-internal
 - In order to enable the transport encryption feature, you will need to install cert-manager
   operator by
   following [the cert-manager operator installation instructions](https://cert-manager.io/docs/installation/).
-- [Eventing installation](./../../install)
+- [Eventing installation](./../../../install)
 
 ## Installation
 
@@ -386,4 +386,4 @@ Example output:
 < date: Thu, 03 Aug 2023 10:08:22 GMT
 < 
 * Connection #0 to host broker-ingress.knative-eventing.svc.cluster.local left intact
-```
+```