Better notebook markup renderer api (#121882)

* Better notebook markup renderer api

For #121256

- Use js modules for notebook output renderers
- Rename apis from `markdown` to `markup`
- Use imports and exports for apis instead of globals for apis
- Use esbuild instead of webpack so we can emit js modules
- Clearly split top level markup renderes from renderers that extend other renderers

* Use constant instead of comment for replacement

extensions/notebook-markdown-extensions/package.json

@@ -18,23 +18,25 @@
     "virtualWorkspaces": false
   },
   "contributes": {
-    "notebookMarkdownRenderer": [
+    "notebookMarkupRenderers": [
       {
         "id": "markdownItRenderer-katex",
         "displayName": "Markdown it katex renderer",
-        "entrypoint": "./notebook-out/katex.js"
+        "entrypoint": "./notebook-out/katex.js",
+        "dependsOn": "markdownItRenderer"
       },
       {
         "id": "markdownItRenderer-emoji",
         "displayName": "Markdown it emoji renderer",
-        "entrypoint": "./notebook-out/emoji.js"
+        "entrypoint": "./notebook-out/emoji.js",
+        "dependsOn": "markdownItRenderer"
       }
     ]
   },
   "scripts": {
     "compile": "npm run build-notebook",
     "watch": "npm run build-notebook",
-    "build-notebook": "npx webpack-cli --config webpack.notebook.js --mode production"
+    "build-notebook": "node ./esbuild"
   },
   "devDependencies": {
     "@iktakahiro/markdown-it-katex": "https://github.com/mjbvz/markdown-it-katex.git",