zh: Fix collection generation

See also: b20fbfe (Fix posts/index.xml RSS feed generation with Hugo v0.153.0, 2025-12-19)

Author: Leo3418

content/zh/collections/_index.md

@@ -0,0 +1,9 @@
+---
+# This file is necessary since Hugo v0.153.0 to even generate pages in
+# collections.  To be more specific, a Git bisect session pointed to Hugo
+# commit 264022a75a8e4d91d7461747eef4d06267cc519f as the change that made this
+# file necessary.  The exact cause of why this file is necessary is still
+# unclear because that commit is unfortunately a very big one tangling 13,654
+# insertions and 5,907 deletions, not following the best Git practices.
+title: "系列文章"
+---