tested with GD32F103C8T6

hardware.md

@@ -3,6 +3,7 @@
 |     Target     |   Board                    | Notes                                       |
 |----------------|----------------------------|---------------------------------------------|
 | stm32f103x6    | bluepill                   |                                             |
+| stm32f103x6    | bluepill with GD32F103C8T6 |                                             |
 | stm32f303xe    | NUCLEO-F303RE + NUCLEO2USB |                                             |
 | stm32f105xb    | NUCLEO-F105RB + NUCLEO2USB | based on NUCLEO-F103RE, direct replacement  |
 | stm32l052x8    | DIY board                  |                                             |

readme.md

@@ -93,7 +93,7 @@ All requirements can be downloaded into a directory specified in environment var
 
 3. Tested with STM32L052K8, STM32L100RC, STM32L476RG, STM32F072C8, STM32F103C8, STM32F103CB,
 STM32F303CC, STM32F303RE, STM32F429ZI, STM32F105RBT6, STM32F107VCT6, STM32L433CCT6, STM32F070CBT6,
-STM32G431RB, STM32F411CEUx, STM32F405RG, STM32F446RE, STM32F373CC, STM32L053R8.
+STM32G431RB, STM32F411CEUx, STM32F405RG, STM32F446RE, STM32F373CC, STM32L053R8, GD32F103C8T6.
 See [hardware.md](hardware.md) for details.
 
 ### Implemented definitions for classes ###