Remove unused contribution files for Docs - Operator

What does this MR do?

The docs site intentionally doesn't translate the Contribute (/development/) docs. Originally, we decided to copy all the development content with only front-matter intact for Japanese under this issue: MVC to hide "Contribute" pages and navigation in Japanese localized docs site. However, the with time, a lot of these development pages are constantly moved, deleted or more pages are created, so this initial MVC doesn't work anymore.

With the Merge Request in place: Derive localized /development pages from English sources, we've now successfully removed the dependency on having any of the /development or contribution files in the /doc-locale directory. Removing the complete directory from the /ja-jp side. There's currently no other /development or /developer files in /fr-fr or /ko-kr

Here's the list of all of the relevant MRs:

1. GitLab: Remove unused contribution files for Docs - GitLab (gitlab-org/gitlab!249035 - merged)
2. Charts: Remove unused contribution files for Docs - Charts (gitlab-org/charts/gitlab!5252 - merged)
3. Runner: Remove unused contribution files for Docs- Runner (gitlab-org/gitlab-runner!7143 - merged)
4. Omnibus: Remove unused contribution files for Docs - Omn... (gitlab-org/omnibus-gitlab!9655 - merged)
5. Operator: Remove unused contribution files for Docs - Ope... (!1603 - merged)

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion.

Required

• Merge Request Title and Description are up to date, accurate, and descriptive
• MR targeting the appropriate branch
• MR has a green pipeline on GitLab.com
• When ready for review, MR is labeled "~workflow::ready for review" per the Distribution MR workflow

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes
• Documentation created/updated
• Tests added
• Integration tests added to GitLab QA
• Equivalent MR/issue for omnibus-gitlab opened
• Validate potential values for new configuration settings. Formats such as integer 10, duration 10s, URI scheme://user:passwd@host:port may require quotation or other special handling when rendered in a template and written to a configuration file.

Related issues

gitlab-com/localization/docs-site-localization#998 (closed)