feat(dev): Document new \OCP\Share\IShareProviderSupportsAllSharesInFolder interface

Signed-off-by: provokateurin <kate@provokateurin.de>

Author: provokateurin

developer_manual/app_publishing_maintenance/app_upgrade_guide/upgrade_to_32.rst

@@ -38,6 +38,7 @@ Added APIs
 
 - New task processing task type ``OCP\TaskProcessing\TextToSpeech`` to convert text to speech.
 - New method ``\OCP\IUser::canChangeEmail`` allowing to check if the user backend allows the user to change their email address.
+- New interface ``\OCP\Share\IShareProviderSupportsAllSharesInFolder`` extending ``\OCP\Share\IShareProvider`` to add the method ``\OCP\Share\IShareProviderSupportsAllSharesInFolder::getAllSharesInFolder```used for querying all shares in a folder without filtering by user.
 
 Changed APIs
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