Extend documentation in download page. Small cleanup in env.

setup/flavors/compose/mailu.env

@@ -24,7 +24,7 @@ SECRET_KEY={{ secret(16) }}
 DOMAIN={{ domain }}
 
 # Mail address of the postmaster
-POSTMASTER={{ postmaster or 'admin'}}
+POSTMASTER={{ postmaster }}
 
 #Chose how secure connections will behave:
 #TLS_FLAVOR={{ tls_flavor }}

setup/flavors/compose/setup.html

@@ -11,8 +11,8 @@ in a project directory. First create your project directory.</p>
 to read and check the configuration variables generated by the wizard.</p>
 
 <pre><code>cd {{ root }}
-wget {{ url_for('.file', uid=uid, filepath='docker-compose.yml', _external=True) }}
+curl {{ url_for('.file', uid=uid, filepath='docker-compose.yml', _external=True) }} > docker-compose.yml
-wget {{ url_for('.file', uid=uid, filepath='mailu.env', _external=True) }}
+curl {{ url_for('.file', uid=uid, filepath='mailu.env', _external=True) }} > mailu.env
 </pre></code>
 {% endcall %}
 
@@ -33,4 +33,17 @@ command.</p>
 <pre><code>cd {{ root }}
 docker-compose up -d
 </pre></code>
+
+Before you can use Mailu, you must create the primary administrator user account. This should be {{ postmaster }}@{{ domain }}. Use the following command, changing PASSWORD to your liking:
+
+<pre><code>docker-compose exec admin python manage.py admin {{ postmaster }} {{ domain }} PASSWORD
+</pre></code>
+
+Login the the admin interface to change the password for a safe one, at
+{% if admin_enabled %}
+one of the hostnames ({{ hostnames }}){{ admin_path }}.
+{% else %}
+http://127.0.0.1:8080 (only directly from the host running docker).
+{% endif %}
+And choose the "Update password" option in the left menu.
 {% endcall %}