adopted documentation on how to create a new file or override an existing file

previous code was outdated and didn't work anymore in newer NC versions (possibly since NC 29)

Signed-off-by: Ronny Bremer <rbremer@almanid.com>

Author: ronnybremer

developer_manual/basics/storage/filesystem.rst

@@ -81,14 +81,13 @@ All methods return a Folder object on which files and folders can be accessed, o
             try {
                 try {
                     $file = $userFolder->get('myfile.txt');
+
+                    // the id can be accessed by $file->getId();
+                    $file->putContent($content);
                 } catch(\OCP\Files\NotFoundException $e) {
-                    $userFolder->touch('myfile.txt');
-                    $file = $userFolder->get('myfile.txt');
+                    $userFolder->newFile('myfile.txt', $content);
                 }
 
-                // the id can be accessed by $file->getId();
-                $file->putContent($content);
-
             } catch(\OCP\Files\NotPermittedException $e) {
                 // you have to create this exception by yourself ;)
                 throw new StorageException('Cant write to file');
@@ -163,4 +162,4 @@ The recommended way of adding your own mounts to the filesystem from an app is i
 and registering the provider using ``OCP\Files\Config\IMountProviderCollection::registerProvider``.
 
 Once registered, your provider will be called every time the filesystem is being setup for a user and your mount provider
-can return a list of mounts to add for that user.
+can return a list of mounts to add for that user.