Aperture priority light meter face (#230)

* initial commit, added opt3001 light meter test app

* tested working light meter board, i2c communication still has issues

* fixed i2c; rudimentary lightmeter works!

* added aperture priority ui

* added aperture priority ui

* added README

* adjusted cal

* fixed bugs (HI shutter speed, lux mode toggle)

* made it possible to advance to the next face

* initialized lux variable

* lowered tolerance for HI and LO

* Changed EV display from always showing EV100 to showing EV[iso setting]

* dont display old ev when ISO changes

* changed mode and light behavior

* updated readme

* fixed indentation

* made lightmeter display logic more consistent

* made lightmeter display logic more consistent

* reverted rules.mk (for merge into upstream)

* reverted rules.mk (for merge into upstream)

* removed OPT3001 PCB model

* made lux mode default, corrected timeout behavior

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Co-authored-by: Christian Chapman <user@debian>

movement/movement_config.h

@@ -29,6 +29,8 @@
 
 const watch_face_t watch_faces[] = {
     simple_clock_face,
+    lightmeter_face,
+    thermistor_readout_face,
     world_clock_face,
     sunrise_sunset_face,
     moon_phase_face,