Add the possibility to link to files

[TillScout]

Expanding on issue 878 here

Like probably many others I use Athens not only for notes or knowledge management, but also for more direct work purposes. In my case this involves a lot of work on documents, which I also share with colleauges. In my company we use MS OneDrive for collaborating on documents.
What would be the killer feature for me is the possibility to link to files in the file system (in my case often in OneDrive folders). It is possible to rather clumsily extract the file location as a text and paste it to Athens, but then it is not formatted as a link. Linking to cloud urls of files is possible and works, but again this is rather clumsy.

In a well made implementation, this would allow for drag&drop support, where I drag a file into the note and this way create a link to the file location.