public IActionResult Edit(int announcementId)
        {
            var model = new ManageAnnouncementModel
            {
                Announcement           = _context.Announcements.Include(x => x.Category).Single(x => x.Id == announcementId),
                AnnouncementCategories = _context.AnnouncementCategories.ToList()
            };

            return(View(model));
        }
        public IActionResult Create()
        {
            var model = new ManageAnnouncementModel
            {
                Announcement           = new Announcement(),
                AnnouncementCategories = _context.AnnouncementCategories.ToList()
            };

            return(View("Edit", model));
        }