LDR Auto brightness

[sblantipodi]

• Breaking changes: requires Firefly Luciferin firmware (v2.9.2).
• Added automatic brightness control using a Light Dependent Resistor (LDR). Documentation here. (Closes #29).
• Luciferin Official PCB has been upgraded to v1.1 to support the new LDR feature.
• Added a brightness limiter feature. Documentation here. (Closes #81).
• This upgrade will format your ESP32. SPIFFS has been deprecated on ESP32 in favour of LittleFS. Please reconfigure WiFi or MQTT if you are using an ESP32 along with the full firmware.** How to here.
• Menu is not visible when taskbar is on top. Fixed. (Closes #86).
• Improved MQTT reconnection. (Closes #85).
• Arduino Bootstrapper update (v.1.13.0).
• PlatformIO Version Increment update (v0.1.7).