chore: Allow script to continue despite errors

- The `|| true` ensures the script continues even if the increment
  operation fails. This prevents the script from halting if
  `CONVERTED` is unset.

scripts/convert-md-tree.sh

@@ -89,7 +89,7 @@ while IFS= read -r -d '' FILE; do
     pandoc $PANDOC_ARGS "$FILE" -s -o "$OUT_FILE"
     echo "✅ Converted: $FILE -> $OUT_FILE"
   fi
-  ((CONVERTED++))
+  ((CONVERTED++)) || true
 done < <(find "$SRC" -type f -name '*.md' -print0)
 
 if $DRY_RUN; then