remove links to groupgets order page

Created by: DBees

https://www.openhwgroup.org/core-v-devkits/

Please remove the section as follows and leave the rest as-is

Ordering the CORE-V MCU DevKit The CORE-V MCU DevKit is currently available for early access order on the GroupGets website with anticipated delivery of November 14, 2023. Visit the GroupGets CORE-V MCU DevKit early access campaign page to reserve your DevKit, as early access quantities are limited.

No need for preview