Add documentation

Author: margaretmeehan

README.md

@@ -150,6 +150,12 @@ Next we need to create a user who can login to the admin site. Run the following
 python manage.py create_admin --noinput --username "admin" --email "[email protected]" --password "password"
 ```
 
+Create the admin, annotator, and annotation approver roles to assign to users. Run the following command:
+
+```bash
+python manage.py create_roles
+```
+
 Developers can also validate that the project works as expected by running the tests:
 
 ```bash
@@ -235,6 +241,12 @@ Click `Labels` button in left bar to define your own labels. You should see the
 
 <img src="./docs/label_editor.png" alt="Edit label" width=600>
 
+### Assign Roles to Users
+
+Click `Users` button in left bar to assign project users to annotator, admin, or annotation approval roles.
+
+<img src="./docs/user_page.png" alt="Edit label" width=600>
+
 ### Annotation
 
 Now, you are ready to annotate the texts. Just click the `Annotate Data` button in the navigation bar, you can start to annotate the documents you uploaded.