docs(turbopack): Move singleton pattern documentation from mdbook to rustdoc #91175

Performance Gate Passed

✅ 17 untouched benchmarks
⏩ 3 skipped benchmarks¹

_{Comparing bgw/turbo-tasks-singleton-docs (6b3646f) with canary (5809756)²}

3 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩
No successful run was found on canary (0b5f67d) during the generation of this report, so 5809756 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩