docs/resource-timeline.md is a stub

[Timi16]

Backlog source: docs/issues/backlog-100-issues.md
Backlog item: I-022
Section: Section B — Architecture and Design Docs (Issues 13–22)
Tag: DOC
Commit context: 9776e85

Observed gap

• docs/resource-timeline.md (579 bytes) is a stub; its content does not match the depth of other feature docs.

Requested outcome

• Turn this backlog item into a concrete repo change in the referenced documentation, tutorial, architecture guide, or contributor workflow.
• Update related cross-links, examples, or adjacent documentation where needed so the change does not leave the docs tree inconsistent.

Completion criteria

• The gap described above is resolved in the repository.
• Any affected docs navigation or contributor guidance remains internally consistent.
• The issue can be closed with a concrete documentation or process change, not just discussion.