FY21-Q2 Product - UX: Help self-managed users to scale better through Reference Architectures

Information formerly referencing “high availability” needs to be reorganized and reworked to emphasize reference architectures.

Working Session: Improve Availability and Scaling Documentation

Scaling and Availability Documentation

KR: All references to HA or high availability are gone (except in Gitaly HA, etc)

KR: Older pages are deprecated, new reference architecture pages are live and linked correctly