Implement devtools chrome extension (#717)

A browser extension that helps you debug Yorkie.

With this extension, you can access the 🐶 Yorkie panel within the
Chrome Developer Tools.

Here's an overview of the Key features:

Left Tab: Document
- Instant access to document keys.
- Visualize the rootObject structure for a comprehensive understanding.

CRDT insights
- Clearly display data types for each CRDTElement using intuitive
  icons and informative tooltips.
- Click on any CRDTElement to unveil datatype-specific details
  tailored to your debugging needs.

View Options
- By default, enjoy a JSON view for quick analysis.
- Explore tree data types with an interactive graph view, offering a
  deeper understanding of the data structure.

---------

Co-authored-by: Youngteac Hong <[email protected]>

config/webpack.config.js

@@ -47,6 +47,7 @@ module.exports = {
   mode: 'production',
   optimization: {
     minimize: false,
+    nodeEnv: false,
   },
   module: {
     rules: [

examples/nextjs-scheduler/app/page.tsx

@@ -124,7 +124,7 @@ export default function Editor() {
       }, 'create default content if not exists');
 
       // 04. subscribe doc's change event from local and remote.
-      doc.subscribe((event) => {
+      doc.subscribe(() => {
         callback(doc.getRoot().content);
       });