"Add new format" to text file without extension
I have a collection of files on my Linux and Mac computers that do not include the ".txt" extension. On Linux and Mac they're not needed.
I've added one such file to my Calibre library, but Calibre does not recognize the contents as plain text. AFAICT Calibre requires that the extension be present, otherwise the contents are treated as an unknown format and the file will contain no data.
If I edit the metadata, I can "add new format," but that does not add formatting information about the current Calibre book. What "add new format" does is let me select a file on my computer that's in some format, and add that file to the Calibre book as an additional format. I will guess that the reason for "add new format" is to allow me as a user to select a nicely-formatted version of a particular format if one is available." But it does not tell Calibre that my current file is in text format, and I can't find any way to do this.
The obvious solution is to change all my text files to have the extension .txt, but that's inelegant. I've read the user manuals and forums but I can't find any other solution.
So... if I have a text file and I want to import it, can I do so without adding a ".txt?"