Refactor Bisaya course exercises for clarity and consistency

- Updated gap fill and multiple choice exercises to streamline content and improve user understanding.
- Simplified question structures and reduced the number of gaps in exercises for better engagement.
- Enhanced explanations for phrases to provide clearer context and meaning for learners.

backend/scripts/create-bisaya-course-content.js

@@ -39,14 +39,14 @@ const BISAYA_EXERCISES = {
       instruction: 'Fülle die Lücken mit den richtigen Bisaya-Wörtern.',
       questionData: {
         type: 'gap_fill',
-        text: 'Kumusta ka? Maayo {gap}. Salamat {gap} palihug.',
-        gaps: 2
+        text: 'Kumusta ka? Maayo {gap}. Salamat.',
+        gaps: 1
       },
       answerData: {
         type: 'gap_fill',
-        answers: ['ko', 'ug']
+        answers: ['ko']
       },
-      explanation: '"Maayo ko" bedeutet "Mir geht es gut" und "ug" verbindet die Wörter.'
+      explanation: '"Maayo ko" bedeutet "Mir geht es gut".'
     },
     {
       exerciseTypeId: 2, // multiple_choice