add code for the HA energy dashboard, monitoring individual devices

[acfnews]

In the HA energy dashboard, you can track/show individual devices. However, each device needs this additional sensor. With this sensor in place, you can add this via:

• Settings
• Dashboards
• Energy
• Individual Devices add $devicename daily energy

From here on, HA shows the airco unit next to other devices, and shows a 'top speaker' like graph.

[arpiecodes]

Hello! Thanks for your contribution. However, it was decided to not include power/energy measurement in the default YAML. This has a couple of reasons, also mentioned in the other pull request at https://github.com/ginkage/MHI-AC-Ctrl-ESPHome/pull/21. It will be better to maybe incorporate a part of it inside the README. Then people can paste it into their YAML and adjust accordingly if they desire to do so.

[acfnews]

will change the location