release-73-2
ICU-22389 Cherry-pick from main to maint-73: CLDR release-43-1-beta1 to ICU main
ICU-21833 remove redundant void parameter lists
ICU-21755 commit-checker: update Tip
ICU-21958 BRS72 Updated ISO currency data URLs
ICU-20033 Add a top-level README.md (#11)
ICU-22220 Add a step to instructions and fix an obsolete path.
ICU-21580 change site.icu-project.org to icu.unicode.org etc
ICU-13392 move IcuCodeTools to separate repo
ICU-21148 Consistently use standard lowercase true/false everywhere.