Update repositories.txt (#6211)

Arduino library for MCP3302 and MCP3304 13-Bit Differential ADC, SPI

Author: RobTillaart

repositories.txt

@@ -5604,6 +5604,7 @@ https://github.com/RobTillaart/MCP23008
 https://github.com/RobTillaart/MCP23017_RT
 https://github.com/RobTillaart/MCP23S08
 https://github.com/RobTillaart/MCP23S17
+https://github.com/RobTillaart/MCP330X
 https://github.com/RobTillaart/MCP3424
 https://github.com/RobTillaart/MCP4261
 https://github.com/RobTillaart/MCP4725