docs: measure the 3.13.0 post against develop with all open pull requests

The baseline is now develop 9c349b1d7c with every open non-draft pull
request merged, including #5968, #5970, #5971, #5975, #5976, #5978,
#5979, #5980, #5981 and #5982. The suite was rerun on 11-01 with every
step repeated when the load rose above 5 while it ran; the comparison
with other libraries and the held-out files were rerun on 10-31.

- suite: 3.0x geometric mean (median 2.9x); Appendix B, the overview
  and the distribution regenerated
- timeline endpoint, Appendix D and the cliffs figure updated
- the held-out figure compares json_document with the fastest other
  library
- new paragraphs for the pull requests listed above

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

docs/mkdocs/scripts/figures/data/perf_timeline.csv

@@ -315,4 +315,4 @@ index,commit,date,pr,subject,parse_twitter,parse_citm,parse_canada,parse_citm_co
 313,21ec9bd801,2026-10-27,5915,json_view: fewer allocations when parsing small documents (#5915),1388.282,2469.118,6066.495,2340.391,1744.901,478.745,214.934,292.970,2309.264,422.842,1323.237,138.541,1454.151,1707.314,178.058,366.514,958.110
 314,2bb2feeef4,2026-10-27,5942,"Fix the red CI on develop (json_view pointer tokens, bson, from_json tests, Infer, IWYU) (#5942)",1391.981,2468.266,6068.495,2335.707,1751.527,482.908,214.285,291.291,2300.453,417.876,1328.089,138.010,1454.934,1701.845,178.250,367.182,964.917
 315,78a0687147,2026-10-27,5940,Strong exception guarantee for operator[](json_pointer) (#5940),1379.414,2467.492,6109.136,2335.309,1723.090,480.260,216.197,292.075,2313.798,415.444,1314.530,138.314,1449.629,1698.792,177.628,364.844,965.314
-316,candidate,,,develop + open pull requests,1402.914,2466.859,6056.321,2327.213,1716.548,486.579,209.924,290.378,2287.966,417.106,1309.461,135.437,1437.370,1702.301,177.011,363.994,991.766
+316,candidate,,,develop + open pull requests,1404.881,2459.645,5976.210,2313.583,1739.023,477.276,214.858,289.366,2301.972,415.963,1307.406,137.828,1440.710,1714.002,176.462,364.414,971.829