Consider post-process analysis data generation for get_table

[d33bs]

While developing a sustainability score for #135 it seemed like there might be an opportunity to explore a section group of functionality which focuses on post-process analytics data handling. The idea here would be to use data from both metrics.yaml and also the compute_repo_data function without interfering with get_table and keeping the functionality distinctions clear.

Originally came up in comment thread brought up by @gwaybio in #208 (comment)