Several document file types use tmd suffix, so at least some txt to tmd conversion possible. You can usually take any plain text files and convert them to documents, either by direct importing or via copy and paste method. In any case, you can only do this in programs that use or support tmd documents.
Convert Simple text file to Tomahawk word processing file.
We have found one software suitable in our database for this conversion.
Microsoft Windows software - convert txt to tmd on Windows
A word processing program and text editor
Convert from txt file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.