Add setting for workspace root

[s-h-a-d-o-w]

If one currently wants to use the oxc extension in a workspace that's not located at the root (and because of other tooling, it might not be possible to just open the sub-directory in vscode), one has to configure up to:

• oxlint binary location
• oxfmt binary location
• tsgolint binary location
• oxlint config location
• oxfmt config location

Seems a bit excessive just point to a sub-directory. Would be great if there was a "workspaceRoot", "basePath" or something setting.

(I have seen #302 and would argue that that's both a different and more complex issue.)

[EnzoAlbornoz]

This would finally fix my VS Code configuration. Currently, mise configures all paths using ${workspaceRoot}. This breaks for oxc because it doesn't support it, so I have to set it up manually.