README: Update to include WB series support.

Author: dpgeorge

README.md

@@ -1,10 +1,10 @@
-STM32 Cube library - CMSIS and HAL for F0, F4, F7, H7, L0 and L4 microcontrollers
-=================================================================================
+STM32 Cube library - CMSIS and HAL for F0, F4, F7, H7, L0, L4 and WB microcontrollers
+=====================================================================================
 
 This repository contains a copy of STMicroelectronic's STM32 Cube firmware
 library, with CMSIS-device and HAL code for STM32F0xx, STM32F4xx, STM32F7xx,
-STM32H7xx, STM32L0xx and STM32L4xx microcontrollers.  Minor changes are
-applied to the HAL source to support MicroPython's port to the STM32.
+STM32H7xx, STM32L0xx, STM32L4xx and STM32WBxx microcontrollers.  Minor changes
+are applied to the HAL source to support MicroPython's port to the STM32.
 
 The "vendor" branch contains the original sources and is updated from
 time-to-time when new versions become available.  The upstream sources are