Create Japanese documentation directory

What does this MR do?

Adding Japanese Documentation Structure

This MR adds a Japanese translated documentation file within a new /doc-locale/ja-jp/ directory structure, which will enable http://docs.gitlab.com/ja-jp/. We're starting with a single translated file to establish the directory structure, with more translations to follow.

Important Notes

1. The docs Hugo project is not currently configured to consume content from the /doc-locale/ directory. When it is, we will iterate on the DOCS_LOCALIZATION_PIPELINE to build the docs in the same way the DOCS_PIPELINE does.
2. We are simply verifying the file is properly linted

Related Changes

This Omnibus MR has sister counterparts across GitLab projects that comprise our documentation site (GitLab, Operator, Charts, & Runner). A change to the docs site will follow to launch docs.gitlab.com/ja-jp/ that will use content from the /doc-locale/ja-jp/ directory.

Please see the SSOT issue for all information related to creating the /doc-locale/ directory structure to launch the Japanese documentation site.

Specific Changes of this MR

1. Creates a new DOCS_LOCALIZATION_PIPELINE rule that is triggered when a branch name is prepended with docs-i18n or comes from https://gitlab.com/gitlab-com/localization/tech-docs-forked-projects/prod/omnibus-gitlab.
2. Creates i18n-specific CI jobs that mirror existing doc CI to lint content:
   • docs-lint-i18n content
   • docs-lint-i18n markdown
3. Adds a single Japanese translated file to /doc-locale/ja-jp/
4. Updates CODEOWNERS to designate @gitlab-com/localization/maintainers as owners of the new /doc-locale directory

How to test these changes

docs-lint-i18n markdown Test markdown linting for localized content

1. Make edits to /doc-locale/ja-jp/build/build_docker_image.md that will fail the markdown linter.
   • For example: remove spaces around lists, use inconsistent heading styles, or add improper indentation
2. Run the linter locally to verify it catches the issues:
   • markdownlint-cli2 'doc-locale/**/*.md'

docs-lint-i18n content Test content linting for localized files

1. Make edits to the Japanese file that will fail Vale rules.
   • For example: remove the frontmatter title key, add corporate jargon, or use passive voice
2. Run Vale locally to see the validation errors:
   • vale --minAlertLevel error doc-locale

Related issues

1. https://gitlab.com/gitlab-com/localization/docs-site-localization/-/issues/102 -> Primary issue with all context related to this work.
2. gitlab-com/localization/docs-site-localization#118 (closed) -> Engineering issue for this MR.

Author's checklist

• Consider taking the GitLab Technical Writing Fundamentals course
• Follow the:
  • Documentation process.
  • Documentation guidelines.
  • Style Guide.
• When ready for review, MR is labeled workflowready for review per the Distribution MR workflow

If you are only adding documentation, do not add any of the following labels:

• ~"feature"
• ~"frontend"
• ~"backend"
• ~"bug"
• ~"database"

These labels cause the MR to be added to code verification QA issues.

Review checklist

Documentation-related MRs should be reviewed by a Technical Writer for a non-blocking review, based on Documentation Guidelines and the Style Guide.

• If the content requires it, ensure the information is reviewed by a subject matter expert.
• Technical writer review items:
  • Ensure docs metadata is present and up-to-date.
  • Ensure the appropriate labels are added to this MR.
  • If relevant to this MR, ensure content topic type principles are in use, including:
    • The headings should be something you'd do a Google search for. Instead of Default behavior, say something like Default behavior when you close an issue.
    • The headings (other than the page title) should be active. Instead of Configuring GDK, say something like Configure GDK.
    • Any task steps should be written as a numbered list.
    • If the content still needs to be edited for topic types, you can create a follow-up issue with the docs-technical-debt label.
• Review by assigned maintainer, who can always request/require the above reviews. Maintainer's review can occur before or after a technical writer review.
• Ensure a release milestone is set.