Add information about request_timeout

Signed-off-by: Dominik Fuchß <develop@fuchss.org>

admin_manual/configuration_files/big_file_upload_configuration.rst

@@ -173,4 +173,10 @@ to the actual file on the Nextcloud servers temporary directory. It is recommend
 the size of your temp directory accordingly and also ensure that request timeouts are high
 enough for PHP, webservers or any load balancers involved.
 
+Federated Cloud Sharing
+-----------------------
+
+If you are using `Federated Cloud Sharing <https://docs.nextcloud.com/server/latest/admin_manual/configuration_files/federated_cloud_sharing_configuration.html>`_ and want to share large files, you can increase the timeout values for requests to the federated servers.
+Therefore, you can set ``davstorage.request_timeout`` in your ``config.php``. The default value is 30 seconds.
+
 .. TODO ON RELEASE: Update version number above on release

admin_manual/configuration_files/federated_cloud_sharing_configuration.rst

@@ -109,6 +109,7 @@ manage federated cloud shares:
 * Check ``Set default expiration date`` to require an expiration date on link 
   shares.
 * Check ``Allow public uploads`` to allow two-way file sharing.
+* If you encounter timeouts for downloading or uploading large files, you can use the option ``davstorage.request_timeout`` in your ``config.php`` to increase the timeout. The default value is 30 seconds.
 
 Your Apache Web server must have ``mod_rewrite`` enabled, and you must have 
 ``trusted_domains`` correctly configured in ``config.php`` to allow external