Aggregate docs from new repo

[aaperis]

Describe the pull request:

• Bug fix
• Functional change
• New feature
• Code cleanup
• Build system change
• Documentation change
• Language translation

Pull request long description:

This PR links the documentation aggregation logic from the sda-pipeline to the sensitive-data-archive repository. Only docs under sda/cmd are linked here since these correspond to components that are merged in and thus expected to get updates.

Some notes to keep in mind:

• backup.md is no longer needed since in the current version of the stack in sensitive-data-archive the backup service has been partially merged with finalize in a way compliant with the FEGA usecase. This change needs to be addressed in the docs throughout.

• notify.md and pipeline.md may be added later after they are migrated under sda/cmd and updated accordingly.

Related issues:

Related issue for migration of docs to the sensitive-data-archive repo: neicnordic/sensitive-data-archive#399 .

Release note:

Aggregate documentation updates from the sensitive-data-archive repository for ingest,verify,finalize,mapper and intercept.