feat() : findMatchingPostByUser 추가

Titto_Backend/src/main/java/com/example/titto_backend/matchingBoard/repository/matchingBoard/MatchingPostRepository.java

@@ -1,7 +1,9 @@
 package com.example.titto_backend.matchingBoard.repository.matchingBoard;
 
+import com.example.titto_backend.auth.domain.User;
 import com.example.titto_backend.matchingBoard.domain.matchingBoard.Category;
 import com.example.titto_backend.matchingBoard.domain.matchingBoard.MatchingPost;
+import java.util.List;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.jpa.repository.JpaRepository;
@@ -12,4 +14,7 @@ public interface MatchingPostRepository extends JpaRepository<MatchingPost, Long
     Page<MatchingPost> findByTitleContaining(String keyword, Pageable pageable);
 
     Page<MatchingPost> findByCategory(Category category, Pageable pageable);
+
+    List<MatchingPost> findMatchingPostByUser(User user);
+
 }