Predefined CI variables for the dependency proxy

See merge request gitlab-org/gitlab!49133

Add the following predefined environment variables:

- CI_DEPENDENCY_PROXY_USER
- CI_DEPENDENCY_PROXY_PASSWORD
- CI_DEPENDENCY_PROXY_HOST
- CI_DEPENDENCY_PROXY_GROUP_URL

Remove future tense from the Front End guide's Vuex section

See merge request gitlab-org/gitlab!49524

Remove future tense from the Front End guide's Performance section

See merge request gitlab-org/gitlab!49521

Add section to the dependency proxy docs detailing CI authentication

See merge request gitlab-org/gitlab!49514

Add sourcegraph feature flag yml

See merge request gitlab-org/gitlab!49442

Add note about npm package names requiring scope higher up in docs

See merge request gitlab-org/gitlab!49404

Revise subheadings about tiers

See merge request gitlab-org/gitlab!49286

More revision of the style guide to reduce wordiness and simplify
language.

Add basic state management to Jira Connect Vue app

See merge request gitlab-org/gitlab!48750

Add service to create Oncall-rotation

See merge request gitlab-org/gitlab!49194

Replace popover with the Glpopover

See merge request gitlab-org/gitlab!49035

Merge branch '283932-flaky-test-qa-specs-features-ee-browser_ui-2_plan-epic-epics_management_spec-rb-39-plan' into 'master'

Move `.js-epic-container` class to fix E2E spec

See merge request gitlab-org/gitlab!49150

`.js-epic-container` was being added to multiple elements which was
causing JS errors

Resolve "DevOps Adoption MVC (backend)"

See merge request gitlab-org/gitlab!48684

Geo: Recover stuck verification started rows

See merge request gitlab-org/gitlab!48006

Follow-up !47131 Apply style guideline

See merge request gitlab-org/gitlab!49496

Disable epic quick actions for new epics

See merge request gitlab-org/gitlab!49470

- Add options to service description

Add specs too

Move CSS to page related bundle

See merge request gitlab-org/gitlab!48792

Add no-global-event-off error to eslint conifg

See merge request gitlab-org/gitlab!49438

Fix spacing and word choice

See merge request gitlab-org/gitlab!49507

Add oncall rotation and participant table

See merge request gitlab-org/gitlab!49058

- Add migrations
- Add models
- Add specs

Update docs for Pages domain config source

See merge request gitlab-org/gitlab!49326

Add closing quotes

Added a note on recommended GitLab Agent setup

See merge request gitlab-org/gitlab!49499

Related to https://gitlab.com/gitlab-org/gitlab/-/issues/220912

Docs cleanup and added kubernetes 1.19 support with support timelines

See merge request gitlab-org/gitlab!49498

Timely sanitization of initial Epic data

See merge request gitlab-org/gitlab!49415