feat: added category entity (response schema) Swagger docs

backend/src/api/categories/entities/category.entity.ts

+import { ApiHideProperty } from '@nestjs/swagger';
 import { Category } from '@prisma/client';
 
 export class CategoryEntity implements Category {
   id: string;
+
+  @ApiHideProperty()
   createdAt: Date;
+
+  @ApiHideProperty()
   updatedAt: Date;
+
+  @ApiHideProperty()
   deletedAt: Date;
+
   name: string;
 }