In the output folder there is now a map#####_eng.pot.

If you want other languages, you can copy this file and name give it the language name of your choosing. For example, name it map12345_ger.pot if your map number was 12345 and your language of choice is German.
Then edit this .po file with a text editor or POEdit and put in all the translations in the msgstr strings. Examples can be found here: https://github.com/dkfans/keeperfx/tree/master/lang/levels/standard
Keep them in the output folder.

When you are done, double click 4_CreateTranslationFiles

Now you are finished. Put the .dat files and the updated .txt file along with your map and it will play in any translation. I strongly recommend keeping the .po and .pot files and bundling them along with the map in case future modifications need to be made.