Rename zh_hans to zh-Hans.

We keep the underscore to help with fallback languages. So in that respect pt_BR
falls back to pt in case of untranslated strings. zh-Hans is a way of writing
Chinese, as is zh-Hant. Neither of them can or should fall back on a
(non-existent) zh language code. They can be combined to form zh-Hans_CN and
zh-Hans_TW if there are ever translators that want to further refine that
dialect.

data/catalogs/apps/diskusage/zh-Hans.catkeys

@@ -0,0 +1,24 @@
+1	simplified_chinese	x-vnd.Haiku-DiskUsage	2324691237
+%a, %d %b %Y, %r	Info Window		%a, %d %b %Y, %r
+%d file	Status View		%d 文件
+%d files	Status View		%d 文件
+9999.99 GB	Status View		9999.99 GB
+Created	Info Window		已创建
+DiskUsage	System name		磁盘查看器
+Free on %refName%	Scanner		空闲存在 %refName%
+Get Info	Pie View		获取信息
+Kind	Info Window		种类
+Modified	Info Window		已修改
+Open	Pie View		打开
+Open With	Pie View		打开方式
+Outdated view	Pie View		过期视图
+Path	Info Window		路径
+Rescan	Pie View		重新扫描
+Rescan	Volume View		重新扫描
+Scan	Status View		扫描
+Scanning %refName%	Scanner		扫描 %refName% 
+Size	Info Window		大小
+file unavailable	Pie View		文件不可用
+file unavailable	Status View		文件不可用
+in %d files	Info Window		其中 %d 个文件
+no supporting apps	Pie View		无可支持应用