Ac6 is introducing the Devicetree Manager for Zephyr, a visual editor for pin muxing and the devicetree of a Zephyr application, and a companion to Workbench for Zephyr.
If you have used STM32CubeMX, the idea is familiar: an interactive chip view where you assign signals to pads, and a properties panel for each peripheral. The difference is that it works from Zephyr's resolved devicetree, the same model for every board and every vendor, so your configuration stays standard Zephyr. On STM32 it covers all STM32 boards.
You enable a peripheral and the tool guides you, flagging the required fields and signals until the configuration is complete, then it generates a boards/<board>.overlay file for your application. It installs automatically with Workbench for Zephyr, and can also be used on its own by pointing it at a Zephyr build directory.
Read more on Devicetree Manager for Zephyr and the step by step tutorials for I2C, USART, SPI and ADC. The reference documentation is at z-workbench.com.