Have the option to create files of different formats

[oanalavinia]

Right now you can only create files that are of Open Document format. At the same time, Collabora Online support multiple formats (see this question) and you can edit such a file if you have it as attachment (uploaded independently of Collabora)

Since other formats are supported, I would like to propose to have the possibility to create files using different formats than the Open Document format.

A configuration could be added to let users specify which formats they would like to use