fix: hide library metadata on block collection pages

Restores the rule from `5ff80d8` that was dropped in a later boilerplate sync. The Library Metadata tables feed the Sidekick library embedded in the Block Collection docs, so they stay in the content but are hidden on the site.

Refs #91

Author: fkakatie

styles/lazy-styles.css

@@ -1 +1,5 @@
-/* add global styles that can be loaded post LCP here */
+/* add global styles that can be loaded post LCP here */
+
+main .library-metadata {
+  display: none;
+}