created announcement admin and reaction inline

widget_princessgabi/announcementboard/admin.py

 from django.contrib import admin
 
-# Register your models here.
+from .models import Announcement, Reaction
+
+class ReactionInLine(admin.TabularInline):
+    model = Reaction
+
+class AnnouncementAdmin(admin.ModelAdmin):
+    model = Announcement
+    list_display = ('title', 'body', 'author', 'pub_datetime')
+    search_fields = ['title', 'body', 'author']
+
+    inlines = [ReactionInLine]