Use imperative tense for CLI help text

flask/cli.py

@@ -724,7 +724,7 @@ def _validate_key(ctx, param, value):
     return value
 
 
-@click.command('run', short_help='Runs a development server.')
+@click.command('run', short_help='Run a development server.')
 @click.option('--host', '-h', default='127.0.0.1',
               help='The interface to bind to.')
 @click.option('--port', '-p', default=5000,
@@ -776,10 +776,10 @@ def run_command(info, host, port, reload, debugger, eager_loading,
                threaded=with_threads, ssl_context=cert)
 
 
-@click.command('shell', short_help='Runs a shell in the app context.')
+@click.command('shell', short_help='Run a shell in the app context.')
 @with_appcontext
 def shell_command():
-    """Runs an interactive Python shell in the context of a given
+    """Run an interactive Python shell in the context of a given
     Flask application.  The application will populate the default
     namespace of this shell according to it's configuration.