Note initial login combination in packager guide

doc/operation_guides/packager/installation-guide.md

@@ -100,7 +100,7 @@ The following steps have to be performed to initiate the actual installation of
 
 # Post-Install Configuration
 
-After the installation of the OpenProject package the system has to be configured to use this package and operate the OpenProject application. Therefore the package includes aconfiguration wizard which can be started using the following command.
+After the installation of the OpenProject package the system has to be configured to use this package and operate the OpenProject application. Therefore the package includes a configuration wizard which can be started using the following command.
 
     openproject configure
 
@@ -117,6 +117,10 @@ The openproject package comes with a command line tool to help manage important
       openproject config:set VAR=VALUE
       openproject reconfigure
 
+
+After you have completed the configuration wizard, the OpenProject instance will be started automatically. You can log into the instance initially with the user/password combination _admin/admin_. You will be asked to change this password immediately after the first login.
+
+
 ## Set configuration options
 
 During the installation process a lot of settings were set to get the application runnings. But if you need to set some advanced options or you want to change some settings which were set during the installation via the installation wizard you can use config:set option. Please be aware that you have to stop and restart the application server so that the new configuration is loaded. This can be done using the service openproject [start|stop] command. See which settings can be set and an example for setting the session store below.