Introduce cd command #3818

Job	Run time
Debug compatibility test	5m 42s
lint	9s
ruby-versions / Generate Ruby versions	2s
rake test 2.7 (latest reline)	1m 30s
rake test 2.7	1m 28s
vterm-yamatanooroti 2.7 (latest reline)	1m 11s
rake test 3.0 (latest reline)	1m 24s
vterm-yamatanooroti 2.7	1m 2s
rake test 3.0	1m 24s
vterm-yamatanooroti 3.0 (latest reline)	53s
rake test 3.1 (latest reline)	1m 31s
vterm-yamatanooroti 3.0	53s
rake test 3.1	1m 29s
vterm-yamatanooroti 3.1 (latest reline)	56s
rake test 3.2 (latest reline)	1m 24s
vterm-yamatanooroti 3.1	59s
rake test 3.2	1m 21s
vterm-yamatanooroti 3.2 (latest reline)	51s
rake test 3.3 (latest reline)	1m 29s
vterm-yamatanooroti 3.2	51s
rake test 3.3	1m 30s
vterm-yamatanooroti 3.3 (latest reline)	51s
rake test head (latest reline)	1m 44s
vterm-yamatanooroti 3.3	54s
rake test head	1m 37s
vterm-yamatanooroti head (latest reline)	55s
rake test truffleruby-head (latest reline)	2m 46s
vterm-yamatanooroti head	58s
rake test truffleruby-head	2m 40s
	40m 24s

Provide feedback