Adding X-axis annotations

[rybe]

Checklist

• I am running the latest version of the card
• I checked if there isn't another feature request opened with the same request
• I checked that the feature is not already available in the dev branch

Describe the solution you'd like
I would like to set markers in my diagram. Similar to how it already works with the “Now” option. To do this, there is the “X-axis annotations” function in apexCharts.js (which is already used for the now option). I want to set n annotations. Perhaps this can then be implemented via a separate series type “xAnnotation” so that data of an entity can be used.

Describe alternatives you've considered
So far, I have used another area series, but unfortunately the text is only available in the legend, which is very confusing.

Additional context
The reason for this feature request is that I want to display the current and future power consumption and would like to mark when, for example, the dishwasher, washing machine or dryer was switched on. This makes it easier to explain the consumption.