Update code/controllers/DocumentationViewer.php
Update code/controllers/DocumentationViewer.php

BUGFIX: fixed mechanism to get nested page entities when using upper case chars as the first char of a markdown files name or a folders name
silverstripe/silverstripe-docsviewer,camfindlay/silverstripe-docsviewer,silverstripe/silverstripe-docsviewer,dhensby/silverstripe-docsviewer,dhensby/silverstripe-docsviewer,camfindlay/silverstripe-docsviewer