Add list of known issues

Author: pan-

README.md

@@ -126,3 +126,10 @@ chosen. For Nordic Semiconductor targets, the following .hex files will be prese
 **Note:** Depending on the build process, the file which has to be flashed on a Nordic target can also be named `<module_name>-combined.hex`. If `<module_name>-combined.hex` and `<module_name>.hex` are present in the build directory, flash `<module_name>-combined.hex.
 
 **Note:** On non Nordic targets, the file to flash can also be named `<module_name>.bin`. Refer to mbed-cli, mbed-os and your board vendor documentation for more informations.
+
+
+Known issues 
+============
+
+* [NUCLEO_F411RE]: Some BLE examples doesn't work with the X-NUCLEO BLE shield. See [#40](https://github.com/ARMmbed/mbed-os-example-ble/issues/40)
+* [NRF5] Impossible to debug or flash the examples with IAR: See [#39](https://github.com/ARMmbed/mbed-os-example-ble/issues/39)