Update README.md

Author: fpistm

Diff for: README.md

@@ -1,4 +1,6 @@
-# Arduino_Core_STM32
+# Arduino core support for STM32 based boards 
+[![GitHub release](https://img.shields.io/github/release/stm32duino/Arduino_Core_STM32.svg)](https://github.com/stm32duino/Arduino_Core_STM32/releases/latest)
+[![GitHub commits](https://img.shields.io/github/commits-since/stm32duino/Arduino_Core_STM32/STM32-2017.8.4.svg)](https://github.com/stm32duino/Arduino_Core_STM32/compare/STM32-2017.8.4...master)
 
 Boards available: