サイド・バーの幅を可変に (#385) (#396)

Reviewed-on: http://git.miteruzo.com/miteruzo/btrc-hub/pulls/396
Co-authored-by: miteruzo <miteruzo@naver.com>
Co-committed-by: miteruzo <miteruzo@naver.com>

frontend/src/pages/posts/PostListPage.tsx

@@ -70,6 +70,7 @@ const PostListPage: FC = () => {
 
   return (
       <div
+	  data-sidebar-container
 	  className="md:flex md:flex-1 overflow-y-auto md:overflow-y-hidden"
 	  ref={containerRef}>
 	<Helmet>