Update documentation for compliance with CommonMark

See merge request gitlab-org/gitlab-ee!7184

Solve conflicts from gitlab-ce/merge_requests!20758

See merge request gitlab-org/gitlab-ee!6812

[EE] Sort labels by reference

See merge request gitlab-org/gitlab-ee!7284

If user has configure the setting then it will be passed to gitlab-shell
and gitlab-workhorse

Fixes conflicts for https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/21545

See merge request gitlab-org/gitlab-ee!7283

[EE] Ask user explicitly about usage stats agreement

See merge request gitlab-org/gitlab-ee!7072

Labels are sorted by reference, not title. This caused random CI
failure.

[EE] Resolve "Remove old storage logic from Import/Export"

See merge request gitlab-org/gitlab-ee!7270

CE upstream - 2018-09-07 00:21 UTC

See merge request gitlab-org/gitlab-ee!7275

[EE] Use ResourceLabelEvent for tracking label changes

See merge request gitlab-org/gitlab-ee!6912

Protected Environments follow up: Use class method to override CE constants on EE

Closes #7204

See merge request gitlab-org/gitlab-ee!7256

don't add empty query params to boards

See merge request gitlab-org/gitlab-ee!4441

Make GitLab.com free trial button primary

See merge request gitlab-org/gitlab-ee!7231

Import common metrics into database (EE)

Closes #6948

See merge request gitlab-org/gitlab-ee!7175

Remove security_reports hash from environment entitity

See merge request gitlab-org/gitlab-ee!7277

We decided that the merged BE implementation needs to be redone.
As the current implementation is not used by any consumer, we should remove it.

For more information see https://gitlab.com/gitlab-org/gitlab-ee/issues/4299

Port 44005-improve-handling-of-projects-shared-with-a-group to EE

See merge request gitlab-org/gitlab-ee!6963

Merge branch '7211-geo-synchronization-does-not-seem-to-replicate-default-branch-all-the-time' into 'master'

Geo - Synchronize the default branch in secondary nodes

See merge request gitlab-org/gitlab-ee!7218