added forms.py

bookshelf/forms.py

+from django import forms
+from .models import Author, Books
+
+class BookForm(forms.ModelForm):
+    class Meta:
+        model = Books
+        fields = '__all__'
+
+class AuthorForm(forms.ModelForm):
+    class Meta:
+        model = Author
+        fields = '__all__'
\ No newline at end of file