fix typos in the documentation

Change-Id: I5585561f9bfa42ea54c992e38dda4b9a89568553

doc/source/user/quickstart.rst

@@ -349,7 +349,7 @@ There are a few options that are required to deploy Kolla-Ansible:
 
   .. end
 
-  To use DockerHub images, the default image tag has to be overriden. Images are
+  To use DockerHub images, the default image tag has to be overridden. Images are
   tagged with release names. For example to use stable Pike images set
 
   .. code-block:: console

releasenotes/notes/horizon_keystone_multidomain-c7a80d670f3654d8.yaml

@@ -2,4 +2,4 @@
 features:
   - |
     Added horizon_keystone_multidomain flag for horizon multidomain support.
-    This flag can be overriden in globals.yml. Default value: False
+    This flag can be overridden in globals.yml. Default value: False