howto.md

@@ -24,6 +24,7 @@ various procedures not necessarily associated with a specific service.
  * [retire-a-host](howto/retire-a-host)
  * [retire-a-user](howto/retire-a-user)
  * [upgrades](howto/upgrades)
+ * [yubikey](howto/yubikey)
 
 ## old