Update README.md

Author: lukasb1b

README.md

@@ -19,7 +19,7 @@ IDE can be downloaded for free at [https://arduino.cc](https://www.arduino.cc/en
 
 -  Follow us on [Twitter](https://twitter.com/arduino)
 -  Explore our [Instagram](https://www.instagram.com/arduino.cc/)
--  Hit the Subscribe button at Youtube .[Youtube](https://www.youtube.com/c/arduino)
+-  Hit the Subscribe button at [Youtube](https://www.youtube.com/c/arduino)
 -  And like us at [Facebook](https://www.facebook.com/official.arduino)
 
 ## Bug reports and technical discussions