New hint anchor reflecting new pre-install check (kubernetes#297)

* New hint anchor reflecting new pre-install check

Signed-off-by: Matej Gera <matejgera@gmail.com>

* Update linkerd.io/content/2/tasks/troubleshooting.md

Co-Authored-By: Kevin Lingerfelt <kl@buoyant.io>
Signed-off-by: Matej Gera <matejgera@gmail.com>

linkerd.io/content/2/tasks/troubleshooting.md

@@ -60,6 +60,12 @@ permissions to install Linkerd.
 For more information on cluster access, see the
 [GKE Setup](/2/tasks/install/#gke) section above.
 
+## √ no clock skew detected {#pre-k8s-clock-skew}
+
+This check verifies whether there is clock skew between the system running
+the `linkerd install` command and the Kubernetes node(s), causing 
+potential issues.
+
 ## The "pre-kubernetes-capability" checks {#pre-k8s-capability}
 
 These checks only run when the `--pre` flag is set. This flag is intended for