alias-pages, subcommand-mention: add Arabic translation (#6821)

contributing-guides/translation-templates/subcommand-mention.md

@@ -6,6 +6,7 @@ In order to notify the user that such sub-command pages exist, we put a little n
 This file contains the translation templates of this notice.
 
 [en](#en) •
+[ar](#ar) •
 [bs](#bs) •
 [da](#da) •
 [de](#de) •
@@ -41,6 +42,13 @@ This file contains the translation templates of this notice.
 Some subcommands such as `example command` have their own usage documentation.
 ```
 
+---
+### ar
+
+```markdown
+بعض الأوامر الفرعية لديها توثيقات الاستخدام الخاصة بها مثل: `example command`
+```
+
 ---
 ### bs