Update repositories.txt (#5565)

Author: krosDC

repositories.txt

@@ -8,6 +8,7 @@ https://github.com/DigitalCodesign/MentorBit-DHT11
 https://github.com/DigitalCodesign/MentorBit-DHT22
 https://github.com/DigitalCodesign/MentorBit-Encoder
 https://github.com/DigitalCodesign/MentorBit-Expander
+https://github.com/DigitalCodesign/MentorBit-LDR
 https://github.com/median-dispersion/Non-Blocking-Melody
 https://github.com/jobitjoseph/ESPWebFileManager
 https://github.com/playfultechnology/PN5180