update index.mdx with correct installation doc ref (hashicorp#19932)

* update index.mdx with correct installation doc ref

update index.mdx with installation doc ref to point to the right installation.mdx path

* Update installation ref

Update installation ref

* Update index ref without relative path

Update installation doc index ref without relative path

website/content/docs/platform/k8s/vso/index.mdx

@@ -30,7 +30,7 @@ The following features are supported by the Vault Secrets Operator:
 - Secret rotation for `Deployment`, `ReplicaSet`, `StatefulSet` Kubernetes resource types.
 - Prometheus instrumentation for monitoring the Operator
 - Supported installation methods: `Helm`, `Kustomize`<br />
-*see the [installation](/vault/docs/platform/k8s/vso/installation.mdx) docs for more details*
+*see the [installation](/vault/docs/platform/k8s/vso/installation) docs for more details*
 
 ## Vault Access and Custom Resource Definitions