Update README.md to reflect Pi 5 channels

Author: colinpate

README.md

@@ -8,6 +8,8 @@ Access the hardware PWM of a Raspberry Pi with Python. More lightweight than alt
 
 1. On the Raspberry Pi, add `dtoverlay=pwm-2chan` to `/boot/config.txt`. This defaults to `GPIO_18` as the pin for `PWM0` and `GPIO_19` as the pin for `PWM1`.
     - Alternatively, you can change `GPIO_18` to `GPIO_12` and `GPIO_19` to `GPIO_13` using `dtoverlay=pwm-2chan,pin=12,func=4,pin2=13,func2=4`.
+    - On the Pi 5, use channels 0 and 1 to control GPIO_12 and GPIO13, respectively; use channels 2 and 3 to control GPIO_18 and GPIO_19, respectively
+    - On all other models, use channels 0 and 1 to control GPIO-18 and GPIO_19, respectively
 2. **Reboot your Raspberry Pi**.
     - You can check everything is working on running `lsmod | grep pwm` and looking for `pwm_bcm2835`
 3. Install this library: `sudo pip3 install rpi-hardware-pwm`