Adds confirmation logs after creating a new project (#12618)

@efriis @hwchase17

---------

Co-authored-by: Erick Friis <erick@langchain.dev>

Author: jacoblee93

libs/cli/langchain_cli/namespaces/app.py

@@ -118,6 +118,13 @@ def new(
     if has_packages:
         add(package, project_dir=destination_dir, pip=pip_bool)
 
+    typer.echo(f'\n\nSuccess! Created a new LangChain app under "./{app_name}"!\n\n')
+    typer.echo("Next, enter your new app directory by running:\n")
+    typer.echo(f"    cd ./{app_name}\n")
+    typer.echo("Then add templates with commands like:\n")
+    typer.echo("    langchain app add extraction-openai-functions")
+    typer.echo("    langchain app add git+ssh://git@github.com/efriis/simple-pirate.git\n\n")
+
 
 @app_cli.command()
 def add(