Add Pimoroni LTR559 driver

[Gadgetoid]

It's my first shot at this- so hopefully the target library is prepared and submodule'd correctly. I've pushed a v0.0.1 release that should be functional and verified that the Release action produces .mpy files for published releases.

Cheers!

[ladyada]

nice work! congrats :)

[dglaude]

I tested with success on:

• Feather M0 Express
• Feather M4 Express
• Feather nRF52840 Express
• Feather STM32F405 Express

(that is using the provided mpy, the latest library bundle and the latest 6.0.0alpha2 firmware)

Possible issues:

• The name is rather long pimoroni_circuitpython_ltr559.mpy and other library do not have "circuitpython" in their name
• The first lux reading is always zero (that could be to avoid delays, it can just be documented that first reading must be discarded)

This driver is very much in Adafruit style. It is a first good step in having a much better support for Enviro+ Feather Wing.

So I would really love to this driver accepted.

If any other testing, do not hesitate to ask.

[ladyada]

@dglaude it was merged. if you have bug reports please submit them on the repo for the library itself