consolidate relatedTarget docs in dropdown event docs
Merge pull request #15090 from twbs/dropdowns-events

consolidate relatedTarget docs in dropdown event docs
Switch to using sub-account of main Sauce account for Savage

Refs commit 6cfd811fcc99e5800c9e6207c48a91f85f699ae7.
Merge pull request #15182 from twbs/sauce-sub-account

Switch to using sub-account of main Sauce account for Savage