feat: add compose ps command

Ps is new command scoped under compose. It is just proxy to `docker
compose ps`.

src/scripts/docker_compose.rs

@@ -18,6 +18,10 @@ pub fn exec(rest: &[String]) -> Result<()> {
         .exec()
 }
 
+pub fn ps() -> Result<()> {
+    CommandBuilder::docker_compose().args("ps").exec()
+}
+
 /// Start containers via `docker compose start`. Optionally pass containers to be started.
 /// ```
 /// start(None);