Fix lint issue.

Signed-off-by: Thomas Hallgren <thomas@tada.se>

Author: thallgren

docs/v2.20/reference/vpn.md

@@ -1,7 +1,8 @@
+import Alert from '@material-ui/lab/Alert';
+
 <!-- TODO: We should figure out a way to make this site-wide without affecting the release notes page -->
 <div class="container">
 
-
 # Telepresence and VPNs
 
 It is often important to set up Kubernetes API server endpoints to be only accessible via a VPN.