Cleanup of (EE) api settings.md doc

What does this MR do?

Related to CE MR https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/20721, and most changes in that MR ported to here.

The EE api settings.md Doc needed a cleanup, due to missing settings, old settings not removed, bad layout, etc. Discussed in issue https://gitlab.com/gitlab-org/gitlab-ce/issues/49155. WIP until some extra details are verified. This MR is split off from https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/6473 to separate docs changes from code changes.

Related to:
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/20721
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/20723
https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/6609

In EE api settings.md:

• Alphabetizes the list.

• Fixes table spacing for readability

• Fixes typo in shared_runners_enabled (true -> boolean)

• sidekiq_throttling_queus Typo in settings.rb, most likely, see https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/20723

• Corrects description of clientside_sentry_dsn

• Update authorized_keys_enabled with description from _performance.html.haml

• (EE Only) Restores shared_runners_text and terminal_max_session_time, hidden accidentally in https://gitlab.com/gitlab-org/gitlab-ee/commit/cdca89df96851cbf93c5203a96a4d3d5af316690

• (EE Only) Added Premium to EE only settings

• Moved table out of the middle of the Change application settings section, and placed in new section at end. pending CE Discussion

• Adds Missing Settings:

  • allow_local_requests_from_hooks_and_services - Description from _outbound.html.haml
  • auto_devops_domain - Description from _ci_cd.html.haml
  • auto_devops_enabled - Description from _ci_cd.html.haml
  • domain_blacklist_raw - Checking
  • domain_whitelist_raw - Checking
  • gitaly_timeout_default
  • gitaly_timeout_fast
  • gitaly_timeout_medium
  • hashed_storage_enabled - Description from _repository_storage.html.haml
  • help_page_text
  • hide_third_party_offers - Description from _third_party_offers.html.haml
  • mirror_available - Description from _repository_mirrors_form.html.haml
  • pages_domain_verification_enabled - Description from _pages.html.haml
  • password_authentication_enabled
  • signin_enabled
  • Add Throttling Settings. Descriptions from _ip_limits.html.haml
    • throttle_authenticated_api_enabled
    • throttle_authenticated_api_period_in_seconds
    • throttle_authenticated_api_requests_per_period
    • throttle_authenticated_web_enabled
    • throttle_authenticated_web_period_in_seconds
    • throttle_authenticated_web_requests_per_period
    • throttle_unauthenticated_enabled
    • throttle_unauthenticated_period_in_seconds
    • throttle_unauthenticated_requests_per_period
  • (EE Only) check_namespace_plan - Description from _account_and_limit.html.haml
  • (EE Only) custom_project_templates_group_id - Not Found
  • (EE Only) external_authorization_service_timeout - Description from external_authorization.html and _external_authorization_service_form.html.haml
  • Updated Mirror settings. Descriptions from _mirror_settings.html.haml
    • (EE Only) mirror_capacity_threshold
    • (EE Only) mirror_max_capacity
    • (EE Only) mirror_max_delay
  • (EE Only) pseudonymizer_enabled Description from application_settings_helper.rb#L47

• Remove Deprecated Settings (no longer in schema.rb) (pending CE Discussion)

  • password_authentication_enabled
  • signin_enabled
  • performance_bar_allowed_group_path
  • performance_bar_enabled

• Changes required to yes for:

  • akismet_api_key
  • clientside_sentry_dsn
  • housekeeping_bitmaps_enabled
  • housekeeping_full_repack_period
  • housekeeping_gc_period
  • housekeeping_incremental_repack_period
  • metrics_port
  • two_factor_grace_period
  • shared_runners_text

Need to check:

Related issues

https://gitlab.com/gitlab-org/gitlab-ce/issues/49155