Use npm to manage litegraph dependency (#45)

* Add comfyui-litegraph dep

* remove static copy

* Remove litegraph impl

* Fix various issues

* LiteGraph import

* Fix test ref issue

* Change to stable version of litegraph

* update README

src/extensions/core/nodeTemplates.ts

@@ -2,6 +2,7 @@ import { app } from "../../scripts/app";
 import { api } from "../../scripts/api";
 import { ComfyDialog, $el } from "../../scripts/ui";
 import { GroupNodeConfig, GroupNodeHandler } from "./groupNode";
+import { LGraphCanvas } from "comfyui-litegraph";
 
 // Adds the ability to save and add multiple nodes as a template
 // To save: