Better error handling when rendering error found when in watch mode

In watch mode it should continue to watch for changes, in any other mode it should exit with a -1 error code so can check for success when scripting

commands/server.go

@@ -45,7 +45,7 @@ func server(cmd *cobra.Command, args []string) {
 		Config.BaseUrl = "http://localhost:" + strconv.Itoa(serverPort)
 	}
 
-	build()
+	build(serverWatch)
 
 	// Watch runs its own server as part of the routine
 	if serverWatch {