server: (UI) add syntax highlighting and latex math rendering (#10808)

* add code highlighting and math formatting

* code cleanup

* build public/index.html

* rebuild public/index.html

* fixed coding style

* fixed coding style

* style fixes

* highlight: smaller bundle size, fix light & dark theme

* remove katex

* add bundle size check

* add more languages

* add php

* reuse some langs

* use gzip

* Revert "remove katex"

This reverts commit c0e5046accd10be3f83018cffdc29a652849fc61.

* use better maintained @vscode/markdown-it-katex

* fix gzip non deterministic

* ability to add a demo conversation for dev

* fix latex rendering

* add comment

* latex codeblock as code

---------

Co-authored-by: Xuan Son Nguyen <son@huggingface.co>

examples/server/webui/package.json

@@ -6,14 +6,19 @@
   "scripts": {
     "dev": "vite",
     "build": "vite build",
-    "preview": "vite preview"
+    "preview": "vite preview",
+    "analyze": "ANALYZE=1 npx vite-bundle-visualizer"
   },
   "devDependencies": {
+    "sass-embedded": "^1.83.0",
     "vite": "^5.4.10"
   },
   "dependencies": {
+    "@vscode/markdown-it-katex": "^1.1.1",
     "autoprefixer": "^10.4.20",
     "daisyui": "^4.12.14",
+    "highlight.js": "^11.10.0",
+    "katex": "^0.16.15",
     "markdown-it": "^14.1.0",
     "postcss": "^8.4.49",
     "tailwindcss": "^3.4.15",