Add text button to modeBarButtons

Hello all,

First of all, thank you for the wonderful tool. It is extremely helpful for our team for building interactive data reports in Python.

I was wondering if there is any way to annotate already existing plots with custom text, the same way a custom shape can be added to the plot. I havenโ€™t found any related option in modeBarButtonsToAdd section of the configuration.

If it is not possible, could this be implemented on the plotly.js level?

Maybe, if you consider this worth adding to, we could try to implement it, as a contribution to the plotly community?