cli: Expand on the status of status

- Add a bit more to the doc info
- Add explicit warning it's not stable

lib/src/cli.rs

@@ -135,6 +135,10 @@ pub(crate) enum Opt {
     /// Change host specification
     Edit(EditOpts),
     /// Display status
+    ///
+    /// This will output a YAML-formatted object using a schema intended to match a Kubernetes resource
+    /// that describes the state of the booted container.
+    /// The exact API format is not currently declared stable.
     Status(StatusOpts),
     /// Add a transient writable overlayfs on `/usr` that will be discarded on reboot.
     #[clap(alias = "usroverlay")]

lib/src/status.rs

@@ -253,6 +253,8 @@ pub(crate) async fn status(opts: super::cli::StatusOpts) -> Result<()> {
         host
     };
 
+    eprintln!("note: The format of this API is not yet stable");
+
     // If we're in JSON mode, then convert the ostree data into Rust-native
     // structures that can be serialized.
     // Filter to just the serializable status structures.