add noise helper library

Author: todbot

.gitmodules

@@ -275,3 +275,6 @@
 [submodule "libraries/drivers/gpio_expander"]
 	path = libraries/drivers/gpio_expander
 	url = https://github.com/gpongelli/CircuitPython_gpio_expander.git
+[submodule "libraries/helpers/noise"]
+	path = libraries/helpers/noise
+	url = https://github.com/todbot/CircuitPython_Noise.git

circuitpython_community_library_list.md

@@ -76,6 +76,7 @@ Here is a listing of current CircuitPython Community Libraries. These libraries
 * [CircuitPython Mag Cal](https://github.com/furbrain/CircuitPython_mag_cal.git) Calibrate magnetic sensors \([Docs](https://circuitpython-mag-cal.readthedocs.io/en/latest/))
 * [CircuitPython_MIDI_Tools](https://github.com/CedarGroveStudios/CircuitPython_MIDI_Tools.git) A collection of methods for processing MIDI notes and Control Change codes. \([Docs](https://github.com/CedarGroveStudios/CircuitPython_MIDI_Tools/blob/main/media/pseudo_rtd_cedargrove_midi_tools.pdf))
 * [CircuitPython MorseCode](https://github.com/jposada202020/CircuitPython_MorseCode.git) ([PyPi](https://pypi.org/project/circuitpython-MorseCode)) \([Docs](https://circuitpython-morsecode.readthedocs.io/en/latest/))
+* [CircuitPython Noise](https://github.com/todbot/CircuitPython_Noise.git) ([PyPi](https://pypi.org/project/circuitpython-noise)) \([Docs](https://circuitpython-noise.readthedocs.io/en/latest/)) Simplex (Perlin-like) noise generation
 * [CircuitPython_OhmsLaw](https://github.com/CedarGroveStudios/CircuitPython_OhmsLaw.git) Calculate an Ohm’s Law result from two input parameters. \([Docs](https://github.com/CedarGroveStudios/CircuitPython_OhmsLaw/blob/main/media/pseudo_rtd_cedargrove_ohmslaw.pdf))
 * [CircuitPython PaletteFader](https://github.com/CedarGroveStudios/CircuitPython_PaletteFader.git) Color palette and list brightness setter and normalizer tool. \([Docs](https://github.com/CedarGroveStudios/CircuitPython_PaletteFader/blob/main/media/pseudo_rtd_cedargrove_palettefader.pdf))
 * [CircuitPython PaletteFilter](https://github.com/CedarGroveStudios/CircuitPython_PaletteFilter.git) Replace color index values in a displayio.Palette object. \([Docs](https://github.com/CedarGroveStudios/CircuitPython_PaletteFilter/blob/main/media/pseudo_readthedocs_palettefilter.pdf))