astroboylrx/PLAN: PLanetesimal ANalyzer v0.3

PLanetesimal ANalyzer (PLAN, Li et al. (2019)) identifies and characterizes planetesimals produced in numerical simulations of the Streaming Instability (Youdin & Goodman 2005) that includes particle self-gravity with code Athena (Stone et al. 2008, Bai & Stone 2010, Simon et al. 2016). PLAN has already been used in the analyses of Li et al. (2018), Abod et al. (2018), and Nesvorný et al. (2019) (featured on the cover of Nature Astronomy), and more studies in progress.