feat(v4): complete event-study df provenance - SunAbraham/dCDH event_… #1473

Job	Run time
Sphinx HTML build (-W warnings as errors)	2m 59s
Validate docs deps install on Python 3.9 (floor compat)	42s
Validate doc snippets + doc-deps integrity	12m 34s
	16m 15s

Provide feedback