docs: Document `version` csv format #977

Job	Run time
build-windows	1m 5s
build-macos (macos-13)	10m 21s
build-linux (containerd-system)	31s
channel (ubuntu-latest)	18s
build-linux (containerd-tarball)	40s
channel (macos-13)	5m 18s
context (ubuntu-latest)	19s
daemon-config (ubuntu-latest)	19s
channel (windows-latest)	22s
context (macos-13)	12m 30s
lima-start-args	5m 59s
daemon-config (macos-13)	8m 29s
context (windows-latest)	48s
daemon-config (windows-latest)	20s
main (ubuntu-latest, v27.3.1)	19s
rootless	20s
set-host	20s
main (ubuntu-latest, type=image,tag=27.3.1)	20s
main (macos-13, v27.3.1)	6m 47s
main (macos-13, type=image,tag=27.3.1)	5m 5s
main (windows-latest, v27.3.1)	31s
main (windows-latest, type=image,tag=27.3.1)	24s
	1h 1m 25s

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