Heat index component

[higbyk]

Describe the component you'd like

I would love to have a component for calculating heat index. This can be done with a template of course, but so can AQI, and it has its own component.
Heat index is commonly calculated and there are several different formulas floating around out there. It would be nice if ESPHome provided a simple and efficient way to calculate this.

What are your use cases for this component?

I use heat index for climate control, for many of my sensors, and have elected to implement it in Home Assistant instead of configuring it in multiple ESPHome configs. I would like to offload these calculations to the ESP devices.

Is there a public datasheet, documentation and/or schematics?

https://en.wikipedia.org/wiki/Heat_index
https://www.wpc.ncep.noaa.gov/html/heatindex_equation.shtml

Anything else?

Consider also adding humidex for our Canadian friends and other common measurements like dew point.

I saw a feature request from 7 years ago that was declined, but that seemed to be a request to enhance an existing component, and it seems sentiment may have changed now that AQI has its own component. Note that AQI also provides multiple formulas (like heat index vs humidex) for different regions.