Digest ymls

[tiffanychu90]

digest

• add an example readable.yml to start readable column names and captions
• update report.ipynb to show the high-level operator stats in great_tables
• move more route name cleaning to time_series_utils so we can use for aggregated monthly service table too
• Research Request - supporting GTFS Digest documentation #1069
• deploy a portfolio testing groupings by route typologies to see how groupings look (partial D4 and D7) for Research Request - GTFS Digest Metrics Shakedown #1059

[github-actions]

nbviewer URLs for impacted notebooks:

• gtfs_digest/report.ipynb

[github-actions]

nbviewer URLs for impacted notebooks:

• gtfs_digest/report.ipynb