Update README.md

Author: yangosoft

README.md

@@ -4,7 +4,7 @@
 
 FFT on audio captured by a mic and displayed on the LCD.
 
-For it uses [KissFFT](https://github.com/mborgerding/kissfft)
+It uses [KissFFT](https://github.com/mborgerding/kissfft)
 
 This is a STM32F429I-DISC1 project using PlatformIO and mbed.