feat: add tex(?) formula support

src/content/posts/markdown-example/index.mdx

@@ -246,4 +246,35 @@ X<sup>n</sup> + Y<sup>n</sup> = Z<sup>n</sup>
 
 Press <kbd>CTRL</kbd>+<kbd>ALT</kbd>+<kbd>Delete</kbd> to end the session.
 
-Most <mark>salamanders</mark> are nocturnal, and hunt for insects, worms, and other small creatures.
+Most <mark>salamanders</mark> are nocturnal, and hunt for insects, worms, and other small creatures.
+
+### Formulas
+Thanks to the [remark-math](https://github.com/remarkjs/remark-math) and [KaTeX](https://katex.org/) , you can write mathematical formulas using LaTeX syntax.
+
+Both inline and block formulas are supported (see example below). Inline formulas can be written like `$$L$$` or `$L$`,
+
+while block formulas can be written like this:
+
+```latex
+$$
+-\frac{\hbar^2}{2m}\nabla^2\psi + V\psi = E\psi
+$$
+```
+
+or
+
+````markdown
+```math
+-\frac{\hbar^2}{2m}\nabla^2\psi + V\psi = E\psi
+```
+````
+
+By default, the reader can copy the formulas in LaTeX format by copy the rendered formulas, unless you set `noClientJavaScript` to `true` in the `config.ts` file.
+
+
+Lift($$L$$) can be determined by Lift Coefficient ($$C_L$$) like the following
+equation:
+
+$$
+L = \frac{1}{2} \rho v^2 S C_L
+$$

src/pages/blog/[...slug].astro

@@ -9,6 +9,7 @@ import ReplyViaEmail from "../../components/ReplyViaEmail.astro";
 import { ExtractFirstImage } from '../../plugins/extract-images';
 import AuthorInfo from "../../components/helper/authors/Info.astro";
 import TableOfContents from "../../components/TableOfContents.astro";
+import "katex/dist/katex.css"
 
 export async function getStaticPaths() {
   const blogEntries = await getCollection('posts');
@@ -62,6 +63,11 @@ const cover = customFeaturedImage || matchedImage_src?.src || firstImageURL || `
         <br>
     <a href="/blog">&larr; Back to posts</a>
     {noscript && <h2>Comments</h2> <Comments path={`blog/${slug}`} />}
+    {!noscript &&
+        <script>
+            import "katex/dist/contrib/copy-tex.js"
+        </script>
+    }
   </div>
 
 </Layout>