Update documentation for whitelist in readme template

readme-vars.yml

@@ -43,6 +43,7 @@ opt_param_env_vars:
   - { env_var: "TRANSMISSION_WEB_HOME", env_value: "/combustion-release/", desc: "Specify an alternative UI options are `/combustion-release/`, `/transmission-web-control/`, and `/kettu/` ." }
   - { env_var: "USER", env_value: "username", desc: "Specify an optional username for the interface" }
   - { env_var: "PASS", env_value: "password", desc: "Specify an optional password for the interface" }
+  - { env_var: "WHITELIST", env_value: "iplist", desc: "Specify an optional list of comma separated host whitelist"}
 opt_param_usage_include_vols: false
 opt_param_usage_include_ports: false
 opt_param_device_map: false
@@ -54,8 +55,6 @@ app_setup_block_enabled: true
 app_setup_block: |
   Webui is on port 9091, the settings.json file in /config has extra settings not available in the webui. Stop the container before editing it or any changes won't be saved.
 
-  For users pulling an update and unable to access the webui setting you may need to set "rpc-host-whitelist-enabled": false, in /config/settings.json`
-
   If you choose to use transmission-web-control as your default UI, just note that the origional Web UI will not be available to you despite the button being present.
 
   ## Securing the webui with a username/password.
@@ -69,6 +68,10 @@ app_setup_block: |
   The automatic update is a shell script that downloads a blocklist from the url stored in the settings.json, gunzips it, and restarts the transmission daemon.
 
   The automatic update will run once a day at 3am local server time.
+  
+  ## Using whitelist
+
+  Use `WHITELIST` to enable an ip of whitelist. Both notation `rpc-whitelist` and `rpc-host-whitelist` are supported. When `WHITELIST` is empty the whitelist is disabled.
 
 # changelog
 changelogs: