Fix the description for the --service flag to run (#237)

It looks like the description was copied from the --ephemeral flag.

main.go

@@ -213,7 +213,7 @@ func init() {
 		DisableFlagParsing: true,
 	})
 	runCmd.Flags().Bool("ephemeral", false, "Run the local command in an ephemeral environment")
-	runCmd.Flags().String("service", "", "Run the local command in an ephemeral environment")
+	runCmd.Flags().String("service", "", "Run the command using variables from the specified service")
 
 	addRootCmd(&cobra.Command{
 		Use:   "protect",