FILEman allows you to very easily insert a link to a file in the text editor using the "File" button you find in the editor toolbar.
Through the file popup you can create a link to a file or insert an image in the editor. You can also upload new files so you don't have to go back and forth to FILEman.
Tip: Because of this double functionality you can disable the Joomla "Image" button and only use the "File" button.
Inserted a file using the "File" button in your text editor:
A modal box will open to selected or upload a file you want to insert: