Webhost: Fix a typo on Start Playing page (ArchipelagoMW#3122)

* add an or

* Changed the wording to account for uploading multiple files

WebHostLib/templates/startPlaying.html

@@ -18,7 +18,7 @@ <h1>Start Playing</h1>
                 <br /><br />
 
                 To start playing a game, you'll first need to <a href="/generate">generate a randomized game</a>.
-                You'll need to upload either a config file or a zip file containing one more config files.
+                You'll need to upload one or more config files (YAMLs) or a zip file containing one or more config files.
                 <br /><br />
 
                 If you have already generated a game and just need to host it, this site can<br />