added books list and detail views to url paths

bellapanghulan_reading/bookshelf/urls.py

 from django.urls import path
 
 from . import views
-from .views import Homepage
+from .views import (Homepage, BooksListView, BooksDetailView)
 
 urlpatterns = [
+    path('books', BooksListView.as_view(), name='books'),
+    path('books/<int:pk>/details', BooksDetailView.as_view(), name='book-details'),
     path('home', Homepage.as_view(), name='home'),
 ]
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