R2 revisions

[bstaton1]

This PR introduces some minor changes to the code following the second round of review, none that affect the analysis or inference.

Changes made:

• Added a figure to compare residuals from snorkel model across years
• Changed title of MS to use "imperfect detection" instead of "detection probability" - in readme and supplement B
• Added calculation of range of posterior median capture probabilities for reporting in-text