term: replace "working tree/dir" for "workspace"? (where appropriate)

[jorgeorpinel]

Extracted from #3245 (comment)

I found it in the following places, at least:

https://github.com/iterative/dvc/blob/de1f67afbd93929d51c5dd052d5f8a951e77c182/dvc/command/gc.py#L15-L17
https://github.com/iterative/dvc/blob/b99c5e4aad6528199ef960d04043f8ffdf3f528c/dvc/repo/brancher.py#L33
https://github.com/iterative/dvc/blob/de1f67afbd93929d51c5dd052d5f8a951e77c182/scripts/completion/dvc.zsh#L76

[jorgeorpinel]

@shcheklein another option is to remove the term "workspace" from everywhere and use "working tree" borrowed from Git/SCM. Not sure it would make sense to use that term for --noscm` projects though.

Related: treeverse/dvc.org#931 (comment)

[jorgeorpinel]

I think this was closed by #3914 no @efiop ? 🙂

[efiop]

@jorgeorpinel Yes! Sorry for the delay. Closing.