[#82]: feat: image entity 생성

BE/src/main/java/com/codesquad/issue/domain/image/Image.java

@@ -0,0 +1,24 @@
+package com.codesquad.issue.domain.image;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@NoArgsConstructor
+@Entity
+@Getter
+public class Image {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    private String url;
+
+    public Image(String url) {
+        this.url = url;
+    }
+}