feat: Add project entity (SCRUM-7) (!7)

Co-authored-by: Phan Huy Tran <p.tran@neusta.de>
Reviewed-on: #7
Reviewed-by: Jan Gleytenhoover <krisellp9@gmail.com>
Co-authored-by: Phan Huy Tran <ptran@noreply.localhost>
Co-committed-by: Phan Huy Tran <ptran@noreply.localhost>

src/main/java/de/szut/lf8_starter/project/ProjectEntity.java

@@ -0,0 +1,41 @@
+package de.szut.lf8_starter.project;
+
+import jakarta.persistence.*;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+import org.springframework.data.annotation.CreatedDate;
+
+import java.time.LocalDate;
+import java.util.List;
+
+@NoArgsConstructor
+@AllArgsConstructor
+@Getter
+@Setter
+@Entity
+@Table(name = "projects")
+public class ProjectEntity {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private long id;
+
+    private String name;
+
+    private long leadingEmployee;
+
+    @ElementCollection
+    private List<Long> employees;
+
+    private long contractor;
+
+    private String contractorName;
+
+    private String comment;
+
+    @CreatedDate
+    private LocalDate startDate;
+
+    private LocalDate endDate;
+}

src/main/java/de/szut/lf8_starter/project/ProjectRepository.java

@@ -0,0 +1,6 @@
+package de.szut.lf8_starter.project;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface ProjectRepository extends JpaRepository<ProjectEntity, Long> {
+}