add say

src/command/say.rs

@@ -0,0 +1,17 @@
+#[derive(Default)]
+pub struct SayCommand {
+    message: String
+}
+
+impl SayCommand {
+    pub fn message(mut self, msg: impl Into<String>) -> Self {
+        self.message = msg.into();
+        self
+    } 
+
+    pub fn build(self) -> super::Command {
+        let message= self.message;
+        let s = format!("say {message}");
+        super::Command(s)
+    }
+}