feat(lib): create markdown-to-html converter

src/app/(blog)/feed/markdown-to-html.ts

@@ -0,0 +1,25 @@
+import { unified } from 'unified'
+
+import remarkParse from 'remark-parse'
+import remarkRehype from 'remark-rehype'
+import rehypeStringify from 'rehype-stringify'
+import remarkGfm from 'remark-gfm'
+import remarkMath from 'remark-math'
+import remarkBreaks from 'remark-breaks'
+import remarkHint from 'remark-hint'
+import rehypeKatex from 'rehype-katex'
+
+export function markdownToHtml(markdown: string) {
+  const file = unified()
+    .use(remarkParse)
+    .use(remarkGfm)
+    .use(remarkMath)
+    .use(remarkBreaks)
+    .use(remarkHint)
+    .use(remarkRehype)
+    .use(rehypeKatex)
+    .use(rehypeStringify)
+    .processSync(markdown)
+
+  return String(file)
+}