Where can I find documentation for using translationStudio (tS)?
The documentation for tS is at translationStudio v11.1 Documentation — translationStudio Information 0.1 documentation.
Direct link to the Desktop (Windows, Mac, Linux) documentation is here: translationStudio for the Desktop: Getting Started — translationStudio Information 0.1 documentation.
The Android docs here: translationStudio for Android™: Getting Started — translationStudio Information 0.1 documentation.
It probably should be mentioned there is also a PDF in the repo, which I found much better than readthedocs as it has screenshots:
(Compare page 53 of PDF with tS for Desktop: Modifying Program Settings — translationStudio Information 0.1 documentation)