add kill

src/command/kill.rs

@@ -0,0 +1,17 @@
+#[derive(Default)]
+pub struct KillCommand {
+    target: Option<super::Selector>
+}
+
+impl KillCommand {
+    pub fn target(mut self, target: super::Selector) -> Self {
+        self.target = Some(target);
+        self
+    }
+
+    pub fn build(self) -> super::Command {
+        let target = self.target.unwrap_or(super::Selector::Executor);
+        let s = format!("kill {target}");
+        super::Command(s)
+    }
+}