Add support for Nucleo64 STM32G070

[kitsunegeisha]

I have no idea why this board is not supported while in the main site clearly refrenced to being supported by arduino

Name: Nucleo64 STM32G070 Link to all relevant information: Documentations : https://www.st.com/resource/en/user_manual/dm00452640-stm32-nucleo64-boards-with-stm32g07xrb-mcus-stmicroelectronics.pdf Where this hardware can be purchased : https://www.st.com/en/evaluation-tools/nucleo-g070rb.html#:~:text=The%20STM32%20Nucleo%2D64%20boards,provided%20by%20the%20STM32%20microcontroller

[MottoYang1997]

I think you can first add the board variant in the ".platformio\packages\framework-arduinostm32" in the same way as adding a custom one in stm32duino. Then you can create a board manifestation JSON file in ".platformio\platforms\ststm32\boards" to create the correct reference to the modified package.