Add subcommands property for subcommand type extensions (#315) #296

Job	Run time
Validate / Config	3s
Validate / DevContainer	7s
Validate / Security	1m 9s
Validate / Smoke	13s
Validate / Lint	32s
Validate / Test (1.25.x, ubuntu-latest)	39s
Validate / Build (1.25.x, ubuntu-latest)	36s
Validate / Build (1.25.x, macos-latest)	47s
Validate / Build (1.25.x, windows-latest)	1m 24s
Validate / Test (1.25.x, windows-latest)	1m 33s
Validate / Test (1.25.x, macos-latest)	36s
Validate / Report	0s
	7m 39s

Provide feedback