DWG ("drawing") is a binary file format used for storing design data and metadata. It is the native format for several CAD packages including AutoCAD. The file format specification is not public available and it is not natively supported by the LayoutEditor. However it can be used by using a converter.
With version 20150718 the LayoutEditor automatic triggers the ODA file converter (former TeighaFileConverter), if it is installed on your system. So DWG files can be loaded and stored as any other file format. So to use DWG, please install the converter on your system. It can freely be downloaded from this link.
Optional other converters can be used. e.g. there is a online converter from Autodesk https://www.autocadws.com/. Other converter can be integrated into the LayoutEditor by using macros.