Update ar.json (#847)

* Update ar.json

* Update ar.json

* remove unnecessary translation

we don't need to translate github, twitter and discord

Co-authored-by: Judicael <46365844+judicaelandria@users.noreply.github.com>

packages/tldraw/src/translations/ar.json

@@ -97,5 +97,10 @@
   "page": "صفحة",
   "keyboard.shortcuts": "اختصارات لوحة المفاتيح",
   "search": "بحث",
-  "loading": "{dots}تحميل "
+  "loading": "{dots}تحميل ",
+  "export.background": "تصدير الخلفية",
+  "transparent": "شـفاف",
+  "auto": "ذاتي",
+  "light": "خفيف",
+  "dark": "غامق"
 }