feat: move uninstall docs

docs/installation/uninstall.md

@@ -2,15 +2,62 @@
 sidebar_position: 10
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-# Uninstalling kube-green
+# Uninstall
 
-## kubectl apply
+:::caution
+To uninstall *kube-green*, you should always use the same process for installing but in reverse.
+:::
 
+Before continuing, ensure that there are not *kube-green* resources in the cluster.  
+You can check it with the following command:
 
-## Helm Chart
+```sh
+kubectl get SleepInfo --all-namespaces
+```
 
+## kubectl
 
-## Operator Lifecycle Manager (OLM)
+:::caution
+The uninstall commands below will delete all *kube-green* CRD in the cluster.  
+If you run undeploy command, the namespace of *kube-green* (by default `kube-green`), will be deleted.
+:::
+
+You can uninstall it using the kubectl `delete` command.
+
+Delete the installation manifests using a link to your currently running *kube-green* version:
+
+```sh
+https://github.com/kube-green/kube-green/releases/download/${RELEASE_TAG}/kube-green.yaml
+```
 
+where `${RELEASE_TAG}` is the tag of the release currently running.
 
 ## kustomize
+
+:::caution
+The uninstall commands below will delete all *kube-green* CRD in the cluster.  
+If you run undeploy command, the namespace of *kube-green* (by default `kube-green`), will be deleted.
+:::
+
+To uninstall kube-green from the cluster, change working directory to the root of *kube-green* repository, and run:
+
+```bash
+make undeploy
+```
+
+## Helm Chart
+
+To uninstall kube-green from the cluster, run:
+
+```sh
+helm uninstall RELEASE_NAME
+```
+
+where `RELEASE_NAME` is the name of the `kube-green` release currently installed.  
+This command, by default, will not delete the CRDs from the cluster, which should be deleted manually.
+
+If you have set the `crds.keep` value to *false* during the installation, also the CRDs will be deleted as well.
+
+## Operator Lifecycle Manager (OLM)
+
+To uninstall kube-green from the cluster, follow [this guide](https://olm.operatorframework.io/docs/tasks/uninstall-operator/).