Allow comparing benchmark results between branches/PRs #33
Description
It would be nice if we could compare the results of two branches, even though it is not entirely clear how that would look like.
Ideas:
- merge matching charts so each chart has both branches' points/lines
- doesn't work well if the two branches were worked on at different times, because the x axis is real time and the points would be far apart
- only compare the last results and show whether the values go up or down
- very different way to display the data, might make more sense for this kind of question but maybe more work