Doc: Made copy of the QML files in the snippets directory

The Delegate.qml and view.qml files were not in the
scope of Qt QML exampledirs. These files were in the example
directory under quick, so had to make of copy of them in the
snippets directory and update the snippet path to get the snippets
in the html output.

Task-number: QTBUG-35445
Change-Id: Ic3fa19dbd36b91d76fbc497ab524f5c0ff91325f
Reviewed-by: J-P Nurmi <jpnurmi@digia.com>
Reviewed-by: Nico Vertriest <nico.vertriest@digia.com>
Reviewed-by: Topi Reiniö <topi.reinio@digia.com>