Merge pull request #252 from dinau/change-readme

Added STM32 Dicscovery to README.md

Author: bogdanm

README.md

@@ -49,7 +49,11 @@ STMicroelectronics:
 * [Nucleo-L152RE](https://mbed.org/platforms/ST-Nucleo-L152RE/) (Cortex-M3)
 * [Nucleo-F030R8](https://mbed.org/platforms/ST-Nucleo-F030R8/) (Cortex-M0)
 * [Nucleo-F401RE](https://mbed.org/platforms/ST-Nucleo-F401RE/) (Cortex-M4)
-* STM32F407 (Cortex-M4)
+* STM32F407 (Cortex-M4F)
+* STM32F0-Discovery (Cortex-M0)
+* STM32VL-Discovery (Cortex-M3)
+* STM32F4-Discovery (Cortex-M4F)
+
 
 Nordic:
 * [nRF51822-mKIT](https://mbed.org/platforms/Nordic-nRF51822/) (Cortex-M0)