chore: Translate transifex_input.json in tr_TR

39% of minimum 30% reviewed source file: 'transifex_input.json'
on 'tr_TR'.

Sync of partially translated files: 
untranslated content is included with an empty translation 
or source language content depending on file format

Author: transifex-integration[bot]

translations/frontend-app-learning/src/i18n/messages/tr_TR.json

@@ -116,7 +116,7 @@
   "learning.outline.goalButton.casual.title": "Öğrenme hedefi stilini belirleyin.",
   "learning.outline.setWeeklyGoal": "Haftalık bir öğrenme hedefi belirleyin",
   "learning.outline.setWeeklyGoalDetail": "Bir hedef belirlemek sizi dersi bitirmeye teşvik eder. Bu hedefi istediğiniz zaman değiştirebilirsiniz.",
-  "learning.outline.start": "",
+  "learning.outline.start": "Derse başla",
   "learning.outline.startBlurb": "",
   "learning.outline.tools": "",
   "learning.outline.upgradeButton": "",