feat(markdown): Migrate to comark for markdown rendering

app/app.vue

@@ -1,6 +1,7 @@
 <script setup lang="ts">
 import '~/assets/css/reset.css';
 import '~/assets/css/base.css';
+import 'katex/dist/katex.min.css';
 
 const { user } = useAuth();
 const { accent, neutral, hinting, refresh: refreshSettings } = await useUserSettings();
@@ -24,7 +25,7 @@ watchEffect(() => {
 });
 
 if (import.meta.client) {
-    // force shiki into browser rendering only
+    // Force Shiki into browser rendering only.
     window.sessionStorage.setItem('mdc-shiki-highlighter', 'browser');
 }
 </script>