Update README.md

Author: kotl

README.md

@@ -22,8 +22,7 @@ The Arduino library is [under heavy development](https://github.com/googlesample
 ## Dependencies
 - FirebaseArduino now depends on [ArduinoJson library](https://github.com/bblanchon/ArduinoJson) instead of containing it's own version of it. Please either use Library Manager or download specific version of the library from github. We recommend that ArduinoJson is at least version [5.13.1](https://github.com/bblanchon/ArduinoJson/tree/v5.13.1)
 
-- ESP8266 Core SDK. We recommend using officially tagged releases and it should be at least [2.4.1]
-(https://github.com/esp8266/Arduino/tree/2.4.1)
+- ESP8266 Core SDK. We recommend using officially tagged releases and it should be at least [2.4.1](https://github.com/esp8266/Arduino/tree/2.4.1)
 
 ## Disclaimer