plot_summs: expressing significance levels

Would it be feasible to express significance levels in plots generate with plot_summs()?
- For a single model plot, one could envision different plot symbols conditional on the significance level. For example, all non-significant coefficients could be plotted with a hallow square symbol, all significant coefficients with filled symbols (* = upside triangle, ** = downside triangle, *** up-down triangles)
- For multiple models, one could continue this coding, with each model having a different color. Alternatively one could consider plotting estimates with different opaqueness, i.e. all non-significant estimates more transparently.
Thanks a lot for considering this feature request

Start by locating the plot_summs() entry point and reading how it builds plots for single and multiple models. Clarify the desired significance thresholds and visual encoding with maintainers; done means an agreed implementation and tests or examples covering both model cases.

Written by the indexing model from the issue text.