Update 'USB config & command protocol'

USB-config-%26-command-protocol.md

@@ -137,7 +137,7 @@ The I2C command format used here is based heavily on the one of [I2C-Tiny-USB](h
 * Get I2C address (`0x00`): gets the address of the virtual temperature sensor device on the I2C bus (the one used in cmd. `0x14`). `0xff` if disabled. Single byte response payload.
 * Set I2C address (`0x01`): sets the address of the virtual temperature sensor I2C device, `0xff` to disable. Single argument byte, two response bytes (old and new addresses).
 * Get temperature (`0x02`): returns the 2-byte 8.4 fixed point temperature, little endian.
-* Get lower temperature limit (`0x03`): returns the 2-byte minimum temperature fore things start going bad.
+* Get lower temperature limit (`0x03`): returns the 2-byte minimum temperature before things start going bad.
 * Get upper temperature limit (`0x04`): returns the 2-byte maximum temperature before things start going bad.
 * Get critical temperature limit (`0x05`): returns the 2-byte critical temperature when things are going really bad.