✨ feat(apps): add description field to all application data files

- add english and chinese description fields to all application data files
- standardize yaml formatting and indentation across all files
- remove BOM characters from several files
- fix tag indentation in multiple files
- update architecture field formatting in DecoTV and wechat-selkies
- fix crossVersionUpdate value from False to false in gitlab applications
- improve description field formatting in billion-mail application

apps/emby/data.yml

@@ -1,4 +1,4 @@
-additionalProperties:
+additionalProperties:
   key: emby
   name: Emby
   tags:
@@ -7,6 +7,9 @@
     - Local
   shortDescZh: 主从式架构的媒体服务器软件
   shortDescEn: A media server software with master-slave architecture
+  description:
+    en: A media server software with master-slave architecture
+    zh: 主从式架构的媒体服务器软件
   type: website
   crossVersionUpdate: true
   limit: 0