Announce Japanese Documentation release in Docs site

Create a banner on the docs site that announces GitLab's Technical Documentation release in Japanese. Expiry date on that banner has to be discussed upon.

Banner message: GitLab Docs is now available in Japanese (ja-JP)

Expiry date: TBD (we possibly need an expiry date to stop showing the banner)

This can be done using the issue template for building a banner: https://gitlab.com/gitlab-org/technical-writing/docs-gitlab-com/-/blob/main/.gitlab/issue_templates/Survey%20banner%20request.md?ref_type=heads

We currently have an active localization disclaimer banner on the development docs as follows: https://gitlab.com/gitlab-org/technical-writing/docs-gitlab-com/-/blob/main/data/ja-jp/l10n-banner.yaml?ref_type=heads