yes: add BENCHMARKING.md

[oech3]

No description provided.

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/misc/io-errors. tests/misc/io-errors is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/misc/tty-eof. tests/misc/tty-eof is passing on 'main'. Maybe you have to rebase?
Skipping an intermittent issue tests/date/date-locale-hour (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/date/resolution (passes in this run but fails in the 'main' branch)
Congrats! The gnu test tests/tail/retry is no longer failing!
Congrats! The gnu test tests/timeout/timeout-group is no longer failing!
Note: The gnu test tests/cp/link-heap is now being skipped but was previously passing.
Note: The gnu test tests/dd/no-allocate is now being skipped but was previously passing.

[codspeed-hq]

Merging this PR will improve performance by 3.12%

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 1 improved benchmark
✅ 310 untouched benchmarks
⏩ 46 skipped benchmarks¹

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	Simulation	du_max_depth_balanced_tree[(6, 4, 10)]	25.9 ms	25.1 ms	+3.12%

---

_{Comparing oech3:yes-bench (d1c28c2) with main (843b202)}

Footnotes

1. 46 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. ↩