PR geerlingguy#81 follow-up: Docs.

README.md

@@ -109,6 +109,10 @@ Extra lines to be inserted in the top-level `http` block in `nginx.conf`. The va
 
 (For Ubuntu only) Allows you to use the official Nginx PPA instead of the system's package. You can set the version to `stable` or `development`.
 
+    nginx_yum_repo_enabled: true
+
+(For RedHat/CentOS only) Set this to `false` to disable the installation of the `nginx` yum repository. This could be necessary if you want the default OS stable packages, or if you use Satellite.
+
 ## Dependencies
 
 None.