Relabel creator button as ICS download

The form button generates the ICS file, so name it after
the result. Move the Nextcloud button ahead of it, matching
the visual weight of the primary actions.

launch.html

@@ -285,12 +285,12 @@
           </div>
           
           <div class="form-actions">
-            <button id="createMeetingButton" class="button primary" type="button" data-i18n="creator.createButton">
-              Create Meeting
-            </button>
             <button id="createNextcloudButton" class="button primary hidden" type="button" data-i18n="creator.nextcloudButton">
                 Create in Nextcloud Calendar
             </button>
+            <button id="createMeetingButton" class="button primary" type="button" data-i18n="creator.createButton">
+              Download ICS File
+            </button>
             <button id="createAdhocButton" class="button secondary hidden" type="button" data-i18n="creator.adhocButton">
               Create Adhoc Link
             </button>