Add bitmap saver library

Author: dastels

.gitmodules

@@ -532,3 +532,6 @@
 [submodule "libraries/drivers/tlv493d"]
 	path = libraries/drivers/tlv493d
 	url = https://github.com/adafruit/Adafruit_CircuitPython_TLV493D.git
+[submodule "libraries/helpers/bitmapsaver"]
+	path = libraries/helpers/bitmapsaver
+	url = https://github.com/adafruit/Adafruit_CircuitPython_BitmapSaver.git

docs/drivers.rst

@@ -334,6 +334,7 @@ Miscellaneous
     74HC595 Shift Register <https://circuitpython.readthedocs.io/projects/74hc595/en/latest/>
     AMG88xx Grid-Eye IR Camera <https://circuitpython.readthedocs.io/projects/amg88xx/en/latest/>
     BD3491FS Audio Processor  <https://circuitpython.readthedocs.io/projects/bd3491fs/en/latest/>
+    Bitmap Saver <https://circuitpython.readthedocs.io/projects/bitmapsaver/en/latest/>
     CAP1188 8-Key Capacitive Touch <https://circuitpython.readthedocs.io/projects/cap1188/en/latest/>
     DRV2605 Haptic Motor Controller <https://circuitpython.readthedocs.io/projects/drv2605/en/latest/>
     DS3502 I2C Potentiometer <https://circuitpython.readthedocs.io/projects/ds3502/en/latest/>