Settings configuration

[graham-mitchell-vcs]

@CoreProduction - There has been a community request to improve the config settings so they are easier to define.

The example code provided in the Core tutorial works well indoors, but saturates at about 3775 lux in direct sunlight (as per VEML6030 specification). I was hoping to discover a couple of gain and integration time commands that could be included in the application code (similar to the SparkFun arrangement) and would be recognised by the PiicoDev_VEML6030.py driver, but your advice below suggests that I have to modify the driver each time I want to vary the gain and integration time.