Improve the graphics in R-Instat through the addition of more geoms

[rdstern]

My claim is that we would substantially enhance the graphics capabilities in R-instat if we had more geoms. I also had the impression that @maxwellfundi became quite a whizz at doing this efficiently. If so, then perhaps this is also something that @Karakacha and @TobbyKe could take over, with initial instruction from @maxwellfundi?

Now the list is getting long and later perhaps we should worry about that! For now I suggest the additions are far more important than adapting that control

On that supposition here is my initial list to add:

a) The remaining geoms in ggplot2. I suggest we should have them all. And there are some that sound really useful! I have put the obviously important ones in bold below. b) The geoms in ggridges as mentioned in #6278 c) geoms and some stats from ggpmisc see #5744 and #5037

From ggplot2 area bin2d blank crossbar errorbar errorbarh function hex linerange path qq qq_line quantile raster rect spoke steps

If you are able to proceed, then I suggest you do a number of pull requests, because there are quite some enhancements here. Not one for each geom, but perhaps 4 or 5 overall with suitable names. for example geom_spoke seems to be useful for circular data.

[maxwellfundi]

@rdstern I have been adding these and i have a few questions

1. On bin2d - I am unsure of all the parameter values possible for statand position- Stat has bin2d and position has identity. What other would you like me to add?
2. on geom_function could you provide the other parameters that can be added on there?
3. on qq what other distributions can be added? I only have - stats::qnorm at the moment

[maxwellfundi]

I think these are more general, for example statistical transformations - statAre they general for these graphs- Would it be a common list of transformations @rdstern or they would be different for each graph?