Add optional SMTP relaying ..

..+ small README update

LocalSettings.php.tmpl

@@ -182,3 +182,13 @@ $wgGroupPermissions['*']['createaccount'] = false;
 
 $wgDebugLogFile = "/var/log/debug-{$wgDBname}.log";
 {{ end }}
+
+{{ if env "SMTP_HOST" }}
+$wgSMTP = [
+    'host'     => '{{ env "SMTP_HOST" }}', // could also be an IP address. Where the SMTP server is located
+    'port'     => 25,                 // Port to use when connecting to the SMTP server
+    'auth'     => false,               // Should we use SMTP authentication (true or false)
+    #'username' => 'my_user_name',     // Username to use for SMTP authentication (if being used)
+    #'password' => 'my_password'       // Password to use for SMTP authentication (if being used)
+];
+{{ end }}