docs: add missing ChargingStation.WebSocketPingInterval to README

Variable was present in OCPP20VariableRegistry but not
documented in the supported variables list.

diff --git a/README.md b/README.md
index a05a0f719e669828adadf7a300dd88f070faeb0b..b65323d42b62f34ab34d4876ea973863e8bae3bd 100644 (file)
--- a/README.md
+++ b/README.md
@@ -724,6 +724,7 @@ All kind of OCPP parameters are supported in charging station configuration or c
 - :white_check_mark: Model (type: string) (units: -)
 - :white_check_mark: SupplyPhases (type: integer) (units: -)
 - :white_check_mark: VendorName (type: string) (units: -)
+- :white_check_mark: WebSocketPingInterval (type: integer) (units: seconds)
 
 #### ClockCtrlr