Guidance for Gitaly, Gitaly Cluster, and Geo capabilities

doc/administration/configure.md

doc/administration/gitaly/faq.md

doc/administration/gitaly/index.md

doc/administration/gitaly/praefect.md

doc/administration/nfs.md

doc/administration/operations/moving_repositories.md

doc/administration/reference_architectures/10k_users.md

doc/administration/reference_architectures/25k_users.md

doc/administration/reference_architectures/2k_users.md

doc/administration/reference_architectures/3k_users.md

doc/administration/reference_architectures/50k_users.md

doc/administration/reference_architectures/5k_users.md

doc/administration/repository_storage_paths.md

doc/api/group_repository_storage_moves.md

doc/api/project_repository_storage_moves.md

doc/api/snippet_repository_storage_moves.md