cmd ref: document target granularity for push/pull/fetch/checkout/status -c et al.

[efiop]

Context: treeverse/dvc/issues/2458, and PRs treeverse/dvc#3002 and treeverse/dvc/pull/3309

UPDATE: See also #886 (comment)

[jorgeorpinel]

A quick draft PR for this would also be great as a couple users have asked about it recently I think but docs are still outdated. I'll get to it eventually if not.

[efiop]

@jorgeorpinel Adding to the next sprint, will try to get to it.

[jorgeorpinel]

@efiop do you remember if dvc list also supports granularity? Yes right? I think also we should include that info, as well as with import and get 🙂

[efiop]

@jorgeorpinel It will support it fully after treeverse/dvc#3825 . Sorry for this hanging for so long, been meaning to get to this for a long time. Definitely need to sort this out for 1.0.