Implementing Command for Echo, no examples

Referring to:

https://github.com/nushell/nushell/blob/main/crates/nu-command/src/commands/core_commands/echo.rs

as the original implementation.

crates/nu-command/src/core_commands/echo.rs

@@ -0,0 +1,32 @@
+use nu_protocol::ast::Call;
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{PipelineData, ShellError, Signature, SyntaxShape};
+//TODO: add Example
+
+#[derive(Clone)]
+pub struct Echo;
+
+impl Command for Echo {
+    fn name(&self) -> &str {
+        "echo"
+    }
+
+    fn usage(&self) -> &str {
+        "Echo the arguments back to the user."
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("echo").rest("rest", SyntaxShape::Any, "the values to echo")
+    }
+
+    fn run(
+        &self,
+        _engine_state: &EngineState,
+        _stack: &mut Stack,
+        _call: &Call,
+        input: PipelineData,
+    ) -> Result<PipelineData, ShellError> {
+        Ok(input)
+    }
+    //TODO: implement fn examples(&self) -> Vec<Example>
+}

crates/nu-command/src/core_commands/mod.rs

@@ -1,6 +1,7 @@
 mod alias;
 mod def;
 mod do_;
+mod echo;
 mod export_def;
 mod for_;
 mod help;
@@ -14,6 +15,7 @@ mod use_;
 pub use alias::Alias;
 pub use def::Def;
 pub use do_::Do;
+pub use echo::Echo;
 pub use export_def::ExportDef;
 pub use for_::For;
 pub use help::Help;

crates/nu-command/src/default_context.rs

@@ -30,6 +30,7 @@ pub fn create_default_context() -> EngineState {
             Def,
             Do,
             Each,
+            Echo,
             ExportDef,
             External,
             For,