Update library list with I2C expander library

Author: ilikecake

circuitpython_community_library_list.md

@@ -25,6 +25,7 @@ Here is a listing of current CircuitPython Community Libraries. These libraries
 * [CircuitPython H3LIS200DL](https://github.com/jposada202020/CircuitPython_H3LIS200DL.git) Driver for the ST H3LIS200DL Accelerometer sensor ([PyPi](https://pypi.org/project/circuitpython-h3lis200dl/)) \([Docs](https://circuitpython-h3lis200dl.readthedocs.io/en/latest/))
 * [CircuitPython HCSR04](https://github.com/mmabey/CircuitPython_HCSR04.git) Library for The HC-SR04 for measuring distances using microcontrollers \([Docs](https://circuitpython-hcsr04.readthedocs.io/en/latest/))
 * [CircuitPython HX711](https://github.com/fivesixzero/CircuitPython_HX711) CircuitPython driver for the HX711 load cell amplifer and ADC \([Docs](https://circuitpython-hx711.readthedocs.io/en/latest/))
+* [CircuitPython I2C Expanders](https://github.com/ilikecake/CircuitPython_I2C_Expanders.git) Driver for various i2C expanders. Current support for PCA9555, PCAL9555, PCA9554, PCAL9554, PCA9538, PCAL9538. ([PyPi](https://pypi.org/project/circuitpython-i2c-expanders/)) \([Docs](https://circuitpython-i2c-expanders.readthedocs.io/en/latest/))
 * [CircuitPython INA3221](https://github.com/barbudor/CircuitPython_INA3221.git) CircuitPython driver for the Texas Instruments' INA3221 3 channels current sensor. \([Docs](https://circuitpython-ina3221.readthedocs.io/en/latest/))
 * [CircuitPython ISL29125](https://github.com/jposada202020/CircuitPython_isl29125.git) Driver for the ISL29125 Light Sensor ([PyPi](https://pypi.org/project/circuitpython-isl29125/) )\([Docs](https://circuitpython-isl29125.readthedocs.io/en/latest/))
 * [CircuitPython JLed](https://github.com/jandelgado/jled-circuitpython) Non-blocking LED effects. \([Docs](https://jandelgado.github.io/jled-circuitpython))