Mention PR arduino-libraries#141 in README

Author: alranel

README.md

@@ -3,6 +3,7 @@
 * https://github.com/arduino-libraries/ArduinoBLE/pull/53
 * https://github.com/arduino-libraries/ArduinoBLE/pull/67
 * https://github.com/arduino-libraries/ArduinoBLE/pull/105
+* https://github.com/arduino-libraries/ArduinoBLE/pull/141
 <!-- pull requests -->
 
 You can consider this as an experimental version of the library, that you can use to test features contributed by the community that haven't been merged yet.