perf: speed up page rendering and jekyll build process (#2034)

- Ensure inline scripts execute after the DOM has fully loaded.
- Use Rollup to bundle the theme-mode and Mermaid scripts, reducing the number of Jekyll include snippets.

_javascript/modules/components.js

@@ -0,0 +1,10 @@
+export { categoryCollapse } from './components/category-collapse';
+export { initClipboard } from './components/clipboard';
+export { loadImg } from './components/img-loading';
+export { imgPopup } from './components/img-popup';
+export { initLocaleDatetime } from './components/locale-datetime';
+export { initToc } from './components/toc';
+export { loadMermaid } from './components/mermaid';
+export { modeWatcher } from './components/mode-toggle';
+export { back2top } from './components/back-to-top';
+export { loadTooptip } from './components/tooltip-loader';