Update README.md

fpistm · web-flow · commit 3effaa7f7685 · 2018-08-09T17:45:38.000+02:00
diff --git a/README.md b/README.md
@@ -1,5 +1,5 @@
 # BoardManagerFiles
-Storage for Arduino Boards Manager JSON and package files etc
+Storage for Arduino Boards Manager JSON and package files for the [STM32 core](https://github.com/stm32duino/Arduino_Core_STM32) support.
 
 **Warning**: release versioning has been changed from date versioning to semantic one. See [Release Versioning change](https://github.com/stm32duino/wiki/wiki/Release-Versioning-change)
 
