Zephyr Workbench, a VSCode extension to manage Zephyr on STM32.
It enables users to easily create, develop, and debug Zephyr applications.
Main features:
Install host dependencies.
Import toolchain and SDK.
Create, configure, build and manage apps.
Debug STM32.
You can directly download it from the VSCode marketplace
For more details, visit the Zephyr Workbench
You can add header file on the project/inc folder by diretly click-right on it and select New> Header file
Or on the general File menu, choose New > Header file, browse to select projet/inc folder.