Update README with new FAP target.

README.md

@@ -12,7 +12,7 @@ Connect the GPS module to power and the USART using GPIO pins 9 (3.3V), 11 (GND)
 
 1. Clone the [flipperzero-firmware] repository.
 2. Create a symbolic link in `applications_user` named `gps`, pointing to this repository.
-3. Compile with `./fbt firmware_gps`. This will create the `gps.fap` binary.
+3. Compile with `./fbt fap_gps`. This will create the `gps.fap` binary.
 
 [Adafruit Ultimate GPS Breakout]: https://www.adafruit.com/product/746
 [minmea]: https://github.com/kosma/minmea