Update README.rst

Co-authored-by: Mark Walker <[email protected]>

README.rst

@@ -62,7 +62,7 @@ To get started with development, clone the repo, and run the following commands:
 
 .. code-block::
 
-    $ pip install -r requirements/django-4.1.txt
+    $ pip install -r requirements/optional.txt django~=4.2
     $ npm install
     $ npm run dev &
     $ python manage.py migrate