docs: Add redirect for old toolchain URL Change-Id: I8dcdc3d85835d59e4067141ace3292748ab76bef Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/491451
Pigweed is an open source collection of embedded-targeted libraries–or as we like to call them, modules. These modules are building blocks and infrastructure that enable faster and more reliable development on small-footprint MMU-less 32-bit microcontrollers like the STMicroelectronics STM32L452 or the Nordic nRF52832.
For more information please see our website: https://pigweed.dev/.