Fixed #22007 -- Fixed cbv docs - make imports consistent

Thanks to trac user kinjal.dixit for the report.

docs/internals/contributing/writing-code/coding-style.txt

@@ -30,6 +30,14 @@ Python style
 * Use ``InitialCaps`` for class names (or for factory functions that
   return classes).
 
+* Use convenience imports whenever available. For example, do this::
+
+      from django.views.generic import View
+
+  Don't do this::
+
+      from django.views.generic.base import View
+
 * In docstrings, use "action words" such as::
 
       def foo():

docs/topics/class-based-views/intro.txt

@@ -71,7 +71,7 @@ something like::
 In a class-based view, this would become::
 
     from django.http import HttpResponse
-    from django.views.generic.base import View
+    from django.views.generic import View
 
     class MyView(View):
         def get(self, request):
@@ -113,7 +113,7 @@ and methods in the subclass. So that if your parent class had an attribute
 ``greeting`` like this::
 
     from django.http import HttpResponse
-    from django.views.generic.base import View
+    from django.views.generic import View
 
     class GreetingView(View):
         greeting = "Good Day"
@@ -198,7 +198,7 @@ A similar class-based view might look like::
 
     from django.http import HttpResponseRedirect
     from django.shortcuts import render
-    from django.views.generic.base import View
+    from django.views.generic import View
 
     from .forms import MyForm