docs: add command to install CRDs using kustomize (#3023)

Signed-off-by: Peter Stolz <50801264+PeterStolz@users.noreply.github.com>

docs/introduction/getting-started.md

@@ -9,7 +9,12 @@ and manages Kubernetes secret resources with ExternalSecret resources.
 
 ## Installing with Helm
 
-The default install options will automatically install and manage the CRDs as part of your helm release. If you do not want the CRDs to be automatically upgraded and managed, you must set the `installCRDs` option to `false`. (e.g. `--set installCRDS=false`)
+The default install options will automatically install and manage the CRDs as part of your helm release. If you do not want the CRDs to be automatically upgraded and managed, you must set the `installCRDs` option to `false`. (e.g. `--set installCRDs=false`)
+
+You can install those CRDs outside of `helm` using:
+```bash
+kubectl apply -k "https://github.com/external-secrets/external-secrets//config/crds/bases?ref=v0.9.11"
+```
 
 Uncomment the relevant line in the next steps to disable the automatic install of CRDs.