Merge pull request #2301 from adamchainz/django_rest_framework_3.15.2

Update Django REST Framework to 3.15.2

lib/docs/scrapers/mkdocs/django_rest_framework.rb

@@ -1,7 +1,7 @@
 module Docs
   class DjangoRestFramework < Mkdocs
     self.name = 'Django REST Framework'
-    self.release = '3.14.0'
+    self.release = '3.15.2'
     self.slug = 'django_rest_framework'
     self.base_url = 'https://www.django-rest-framework.org/'
     self.root_path = 'index.html'