feat: enhance accessibility and language support across components

- Updated various components to include `lang` attributes for improved accessibility and SEO.
- Introduced a new `env.d.ts` file to define environment variables for better type safety.
- Adjusted the print width in `.prettierrc.mjs` for improved code formatting.
- Streamlined the `Header`, `PostElement`, and `SocialLinks` components for better structure and clarity.
- Added language support to blog posts and updated the layout to reflect these changes.

src/components/Comments.astro

@@ -15,6 +15,7 @@ const theme = "transparent_dark";
 
 <script
 	is:inline
+	defer
 	src="https://giscus.app/client.js"
 	data-category-id={categoryId}
 	data-category={category}