Once you have created individual .lu files you can parse them all to a QnA Maker JSON model using this command:
> ludown parse toqna -l <folder with .lu files> [-s -o <outputfolder> -n <QnAKBName> --verbose]
This will parse all .lu files found and will create ONE QnA Maker JSON model.
If you would like to create multiple QnA Maker KB's, then you can add a root.lu file that holds reference to other relevant .lu files and parse it like this:
> ludown parse toqna --in <root_file.lu> [-o <outputFolder> -n <QnAKBName> --verbose]
This will parse all .lu files referenced in the root_file.lu and output ONE QnA Maker JSON model.
You can use ludown to parse and compile all word alterations/ synonyms list that can then be used to replace your existing QnA Maker alterations list.
See here for defining word alterations/ synonyms list in .lu files.
> ludown parse toqna --write_qna_alterations --in <root_file.lu> [-o <outputFolder> -n <QnAKBName> --verbose]
> qnamaker create kb --in _qnaKB.json --subscriptionKey <key> --hostname <url> --endpointKey <key>
> qnamaker replace alterations --in _Alterations.json --subscriptionKey <key> --hostname <url> --endpointKey <key>
Note: You can install the QnAMaker CLI from here