feat: enhance typography and image handling

- Add Heti typography plugin for improved Chinese text layout
- Implement rehype plugin to convert images to figure elements with captions
- Update UnoCSS configuration by removing typography preset
- Modify file extensions for consistency (.mjs to .js)
- Add new plugins for admonition, GitHub card, and reading time components
- Improve image and text styling with Heti CSS

.vscode/settings.json

@@ -65,12 +65,16 @@
     "bmoji",
     "Frontmatter",
     "gtag",
+    "Heti",
     "katex",
     "Lightbox",
     "mdast",
     "msrc",
     "msvalidate",
+    "noopener",
+    "noreferrer",
     "overlayscrollbars",
+    "pagefind",
     "partytown",
     "photoswipe",
     "pswp",