Add submission # 6499

#6499

Author: ArduinoBot

registry.txt

@@ -8252,3 +8252,4 @@ https://github.com/ahmadfathan/DMD32Plus.git|Contributed|DMD32Plus
 https://github.com/dwan6767/lowkeyssd1306.git|Contributed|lowkeyoled
 https://github.com/Init-io/InitJson.git|Contributed|InitJson
 https://github.com/ArtronShop/ArtronShop_BL0940.git|Contributed|ArtronShop_BL0940
+https://github.com/Init-io/InitMQTT.git|Contributed|InitMQTT