doc for library interfacing LED matrix displays

 Library interfacing LED matrix displays with the MAX7219 driver
 (using SPI), WS2812 (NeoPixels, inc Pimoroni Unicorn pHat/Hat
 and Unicorn Hat HD) and APA102 (DotStar) on the Raspberry Pi
 and other Linux-based single board computers - it providesxi
  a Pillow-compatible drawing canvas, and other functionality to support:
    multiple cascaded devices
    LED matrix, seven-segment and NeoPixel variants
    scrolling/panning capability,
    terminal-style printing,
    state management,
    dithering to monochrome,
    pygame emulator
    Package contains documentation