Missing documentation: propertiesReader without any arguments for creating a new empty properties object.

[ghuser]

I thought that it was not possible to create an empty properties object using the propertiesReader constructor and it took me some time looking at the code to figure out that it is possible.

It would be nice adding an example in the documentation. e.g.

const properties = propertiesReader();
properties.set('propName', 'propValue')
await properties.save('outputfile.properties');