With the rewrite of the Installation Guide from a PDF document to now being a QML application came the option to fully translate it using Transifex.
https://www.transifex.com/kaos/kaos/welcomets/
https://www.transifex.com/organization/kaos/dashboard/kaos
Help will be needed to get this fully translated since it is a rather large document with many strings. So any help with this will be much appreciated, plus proofreading is needed too. For that you can see the translations strings or install the Welcome app and click on the Guide button.
You can open pull requests for any spelling or grammar errors you may find.
https://github.com/KaOSx/welcome_qml