[extensions-web] readme: fixed typo

[Yuri Konotopov <ykonotopov src gnome org>]

commit e8b7731222249d8a857049b406008779efae936e
Author: Yuri Konotopov <ykonotopov gnome org>
Date:   Tue Apr 2 21:28:56 2019 +0400

    readme: fixed typo

 README.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/README.rst b/README.rst
index a02aa05..f853ab2 100644
--- a/README.rst
+++ b/README.rst
@@ -100,7 +100,7 @@ Once you've done that, proceed with the database migrations:
 
   $ python manage.py migrate
   $ python manage.py compilemessages
-  $ python mange.py createsuperuser --username=joe --email=joe email com
+  $ python manage.py createsuperuser --username=joe --email=joe email com
 
 After above steps your database should be initialized and almost ready to run.