improved sdk_fix readme

Author: Stefan Kremser

sdk_fix/README.txt

@@ -1,4 +1,4 @@
-Copy these files and past them at the location.
+Copy and replace the files at these locations:
 
-user_interface 				--->  \packages\esp8266\hardware\esp8266\2.0.0\tools\sdk\include
-ESP8266WiFi.cpp and ESP8266WiFi.h 	--->  \packages\esp8266\hardware\esp8266\2.0.0\libraries\ESP8266WiFi\src
+user_interface.h -> \packages\esp8266\hardware\esp8266\2.0.0\tools\sdk\include
+ESP8266WiFi.cpp and ESP8266WiFi.h -> \packages\esp8266\hardware\esp8266\2.0.0\libraries\ESP8266WiFi\src