Update configuration.md and improve config env.mapping list. #13883

Job	Run time
check_if_release_branch	1s
changed_files	8s
towncrier_check	6s
build mirrord CLI	0s
check-rust-docs	1m 1s
lint	3m 38s
lint_markdown	0s
integration_tests	12m 1s
macos_tests	21m 0s
test_agent	3m 27s
test_agent_image	6m 10s
test_cli_image	7m 35s
e2e (docker)	14m 32s
vscode_e2e_on_release_branch	0s
e2e (containerd)	10m 29s
intellij_e2e_on_release_branch	0s
ci	1s
	1h 20m 9s

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