Improve Preview / Code examples

[techniq]

• [ ] Consider switching from PrismJS to Shiki syntax highlighting
  • https://github.com/shikijs/shiki
  • https://rodneylab.com/sveltekit-shiki-syntax-highlighting/
    • https://github.com/rodneylab/sveltekit-shiki-code-highlighting
  • https://joyofcode.xyz/sveltekit-markdown-blog#syntax-highlighting
• [ ] Support tailwind configuration
  • https://github.com/bennymi/svhighlight (highlight.js based)
• [ ] Improve preprocessor
  • https://github.com/metonym/svelte-preprocess-highlight/blob/master/src/index.ts
  • https://www.svelteui.org/preprocessors/view-source
  • https://github.com/svelteuidev/svelteui/blob/main/packages/svelteui-preprocessors/src/SourceCode/preprocess.ts