Update mdx.doc-reader.ts

Co-authored-by: Copilot <[email protected]>

Author: GiladShoham

scopes/mdx/mdx/mdx.doc-reader.ts

@@ -8,7 +8,7 @@ export class MDXDocReader implements DocReader {
 
   async read(path: string, contents: Buffer) {
     const output = compileSync(contents.toString('utf-8'), mdxOptions);
-    const metadata = output.data.frontmatter as any;
+    const metadata = output.data?.frontmatter ?? {};
 
     const doc = Doc.from(path, metadata);
     return doc;