feat: add callout support (#655)

* feat: toggle .dark class on theme change

* feat: add callouts with rehype-callouts plugin

* docs: update blog posts with callouts

astro.config.ts

@@ -10,6 +10,7 @@ import sitemap from "@astrojs/sitemap";
 import { unified } from "@astrojs/markdown-remark";
 import remarkToc from "remark-toc";
 import remarkCollapse from "remark-collapse";
+import rehypeCallouts from "rehype-callouts";
 import {
   transformerNotationDiff,
   transformerNotationHighlight,
@@ -40,6 +41,7 @@ export default defineConfig({
         remarkToc,
         [remarkCollapse, { test: "Table of contents" }],
       ],
+      rehypePlugins: [rehypeCallouts],
     }),
     shikiConfig: {
       themes: { light: "min-light", dark: "night-owl" },