Initial drafts of plots in R using ggplot2 for milestone 3

[brendoncampbell]

Progress so far for one of our plots. I haven't been able to get the fill = stat() argument to correctly display the desired heat map values/colours the same way we did in Altair. I know count isn't the appropriate function here but it produces a reasonable looking draft plot :). Heatmaps are a bit of a hack in ggplot2