[Feature Request] Add power consumption in Watts

[treeDweller98]

Monitoring charging speeds and power draw is useful. A simple +/- W indicator like this GNOME extension that I used back before the update:

https://extensions.gnome.org/extension/4862/bat_consumption_wattmeter/

[rwxroot]

@ada4a any thoughts on this? I briefy looked for crates but none looked good enough.

[ada4a]

This looks like something sysinfo could very well support 🤔 But for now, it looks like we'd need to read /sys manually, like this Gnome extension does:

https://github.com/ferdef/power_consumption/blob/10e489d1a01c1a13f82f541b5153c773b439b6ad/extension.js#L54-L60

Personally I'm not interested in this feature and so wouldn't work on a PR myself, but happy to review. @treeDweller98 we've had several people add support for new indicators, and it all followed a similar scheme, so if you'd like to give it a try yourself, that'd be very welcome:)