Fix typo for slot name.

See merge request !2737

[EE] Gitaly apply gitattributes

See merge request !2702

Fix advanced search syntax for commits

Closes #3011

See merge request !2709

[ci skip]

[ci skip]

Extend documentation on writing EE features

See merge request !2248

Used to guard EE-licensed features.

CE upstream: Friday

Closes gitaly#464, gitlab-com/community-writers#40, gitlab-ce#36618, gitaly#468, #3149, gitlab-ce#36492, and gitlab-ce#3646

See merge request !2710

* ee/master:
  Geo - Remove unnecessary param from Geo::BaseSyncService#update_registry
  [ci skip] Geo: add documentation on what selective replication support
  Update multi_project_pipeline_graphs.md
  Drop unnecessary timestamp columns in Geo event tables