M30 configure yaml for ESPhome

[edalquist]

Here is an updated ESPHome config: https://gist.github.com/edalquist/42c6f8...a66ba41d59

It has a bunch of tweaks:
* Defines device_class and state_class for all sensors which enables statistics in home assistant and allows integration with the various energy monitoring features
* Allow setting max-current for each sensor via an input slider, this is used to control the LED color
* Set a global LED brightness