Add Nextcloud 20 support

Signed-off-by: Christoph Wurst <[email protected]>

Author: ChristophWurst

lib/index.ts

@@ -1,6 +1,6 @@
 /// <reference types="@nextcloud/typings" />
 
-declare var OC: Nextcloud.v16.OC | Nextcloud.v17.OC | Nextcloud.v18.OC | Nextcloud.v19.OC;
+declare var OC: Nextcloud.v16.OC | Nextcloud.v17.OC | Nextcloud.v18.OC | Nextcloud.v19.OC | Nextcloud.v20.OC;
 
 /**
  * Get an absolute url to a file in an app