Added start read date

internal/model/userbook.go

@@ -1,14 +1,19 @@
 package model
 
-import "gorm.io/gorm"
+import (
+	"time"
+
+	"gorm.io/gorm"
+)
 
 // describes the relationship between a user and a book.
 type UserBook struct {
 	gorm.Model
-	UserID   uint
-	BookID   uint
-	Book     Book
-	Rating   int
-	Read     bool
-	WantRead bool
+	UserID        uint
+	BookID        uint
+	Book          Book
+	Rating        int
+	Read          bool
+	WantRead      bool
+	StartReadDate *time.Time
 }