Better document how settings injection works with OpenShift

Fixes #1050
Signed-off-by: Michal Čihař <michal@cihar.com>

docs/admin/deployments.rst

@@ -231,9 +231,9 @@ Customize Weblate Configuration
 You can customize the configuration of your Weblate installation on OpenShift
 through environment variables.  Override any of Weblate's setting documented
 under :ref:`config` using ``rhc env set`` by prepending the settings name with
-``WEBLATE_``. The variable is parsed as Python string, after replacing
-environment variables in it (eg. ``$PATH``). To put literal ``$`` you need to
-escape it as ``$$``.
+``WEBLATE_``. The variable content is put verbatim to the configuration file,
+so it is parsed as Python string, after replacing environment variables in it
+(eg. ``$PATH``). To put literal ``$`` you need to escape it as ``$$``.
 
 For example override the ``ADMINS`` setting like this: