<!--IssueSummary start--> <details> <summary> Everyone can contribute. [Help move this issue forward](https://handbook.gitlab.com/handbook/marketing/developer-relations/contributor-success/community-contributors-workflows/#contributor-links) while earning points, leveling up and collecting rewards. </summary> - [Close this issue](https://contributors.gitlab.com/manage-issue?action=close&projectId=278964&issueIid=413221) </details> <!--IssueSummary end--> This is a follow-up from https://gitlab.com/gitlab-org/gitlab/-/merge_requests/114921#note_1322163624 We should update our [Direct transfer documentation](https://docs.gitlab.com/ee/development/bulk_import.html) with the following information: 1. Explain the NDJSON pipelines 1. Explain how the source instance generates the NDJSON files 1. Explain project migrations 2. Update the diagram /cc @rodrigo.tomonari @georgekoltsov @m_frankiewicz