document how branchIndex works

[despairblue]

This documents the changes made here: n8n-io/n8n#9760

Changed page: https://docs.n8n.io/code/builtin/output-other-nodes/

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[github-actions]

Overall readability score: 41.92 (🟢 +0.01)

File	Readability
output-other-nodes.md	63.5 (🟢 +7.01)

View detailed metrics

🟢 - Shows an increase in readability
🔴 - Shows a decrease in readability

File	Readability	FRE	GF	ARI	CLI	DCRS
output-other-nodes.md	63.5	51.07	9.4	14.5	10.27	6.21
	🟢 +7.01	🔴 -0.31	🟢 +0.29	🟢 +2.1	🟢 +1.33	🟢 +0.51

Averages:

	Readability	FRE	GF	ARI	CLI	DCRS
Average	41.92	34.81	12.02	15.15	14.26	8.64
	🟢 +0.01	🟢 +0	🟢 +0	🟢 +0	🟢 +0	🟢 +0

View metric targets

Metric	Range	Ideal score
Flesch Reading Ease	100 (very easy read) to 0 (extremely difficult read)	60
Gunning Fog	6 (very easy read) to 17 (extremely difficult read)	8 or less
Auto. Read. Index	6 (very easy read) to 14 (extremely difficult read)	8 or less
Coleman Liau Index	6 (very easy read) to 17 (extremely difficult read)	8 or less
Dale-Chall Readability	4.9 (very easy read) to 9.9 (extremely difficult read)	6.9 or less

[despairblue]

@StarfallProjects the change has been merged and should be in 1.47. Let me know if the explanation is confusing. Happy to amend it.

I added the label in-next-release. I hope that's correct.