Update creating-command-line-tools.rst to fix typo

The import statement, as written, fails. It doesn’t match the name of the file that is set up with the greet() function.

Author: arrowtype

source/guides/creating-command-line-tools.rst

@@ -78,7 +78,7 @@ in :file:`cli.py`:
 
     import typer
 
-    from .hello import greet
+    from .greet import greet
 
 
     app = typer.Typer()