options to pass to cargo, whether cargo needs to be online, and
whether cargo might want to update `Cargo.lock`.
- nailing-cargo knows about `update`, `generate-lockfile` and
- `fetch`; all other subcommands are (silently) treated the same way
+ nailing-cargo knows about the following commands:
+ * `fetch`
+ * `generate-lockfile`
+ * `update`
+
+ All other subcommands are (silently) treated the same way
as `build` (ie, no subcommand properties). See
`--subcommand-props` for more detail about how the
subcommand affects nailing-cargo's behaviour.