Pull request #981: DEV-22426: removing episodes in strata without exposure group heterogeneity
Merge in SENTINEL/sentinel-routine-querying-tool-documentation from DEV-22426 to staging
* commit 'b279268cbb8520ad6b7f375ae108aecd17d13e2f':
DEV-22426: Add DROPPEDSTRATA and update PS stratification func doc
DEV-22426: updates per feedback
DEV-22426: add section about removing episodes in strata without exposure group heterogeneity
