add beginning of GI review

[kweav]

Started Genetic Interaction calculation review and have some questions on how the GI Mapping results compare to the gimap results. This Rmd shows some of the early differences I'm observing.

[cansavvy]

So the difference between the two sets is that the old version of the GI scores has GI scores for single targets as well as double targets.

Whereas I have the single target GI scores in their own columns "single_target_gi_score_1" and "single_target_gi_score_2" the old table puts each of these in their own row.