Update the mozilla sops decryption with HashiCorp Vault section

Update that section to reference the kustomize-controller doc, now that
we support hc-vault decryption directly in the controller code.

Signed-off-by: Soule BA <soule@weave.works>

content/en/docs/guides/mozilla-sops.md

@@ -191,58 +191,9 @@ Encrypting with age follows the same workflow than PGP. See the [Kustomization-c
 
 ## Encrypting secrets using HashiCorp Vault
 
-Sops needs a valid Vault token in an environment variable named `VAULT_TOKEN` to decrypt the secrets.
+[HashiCorp Vault](https://www.vaultproject.io/docs/what-is-vault) is an identity-based secrets and encryption management system.
 
-Create a Kubernetes secret named `sops-vault-token` in the `flux-system` namespace:
-
-```sh
-kubectl create secret generic sops-vault-token \
---namespace=flux-system \
---from-literal=token=$VAULT_TOKEN
-```
-
-[Customize your Flux Manifests](../installation/_index.md#customize-flux-manifests) so that kustomize-controller has the proper credentials.
-Patch the kustomize-controller Pod template so that the `VAULT_TOKEN` environment variable is set:
-
-`clusters/cluster0/flux-system/kustomization.yaml`
-```yaml
-apiVersion: kustomize.config.k8s.io/v1beta1
- kind: Kustomization
- resources:
- - gotk-components.yaml
- - gotk-sync.yaml
- patches:
-   - path: sops-kustomize-patch.yaml
-     target:
-       kind: Deployment
-```
-
-`clusters/cluster0/flux-system/sops-kustomize-patch.yaml`
-```yaml
-apiVersion: apps/v1
- kind: Deployment
- metadata:
-   name: kustomize-controller
-   namespace: flux-system
- spec:
-   template:
-     spec:
-       containers:
-       - name: manager
-         env:
-           - name: VAULT_TOKEN
-             valueFrom:
-               secretKeyRef:
-                 name: sops-vault-token
-                 key: token
-```
-
-At this point, kustomize-controller is now authorized to decrypt values in
-SOPS encrypted files from your Sources via the related Vault instance.
-
-See Mozilla's guide to
-[Encrypting using Hashicorp Vault](https://github.com/mozilla/sops#encrypting-using-hashicorp-vault)
-to get started committing encrypted files to your Git Repository or other Sources.
+Encrypting with HashiCorp Vault follows the same workflow than PGP & Age. See the [Kustomization-controller API doc](/docs/components/kustomize/kustomization/#hashicorp-vault) for more details.
 
 ## Encrypting secrets using various cloud providers