I’m embodying an archetype here, but I can’t resist.
The use of QTermWidget makes this almost entirely an exercise in building a hello-world Qt app and very little about building a terminal. That is all very well if you are looking to learn Qt—which is by no means an unworthy aim—but I wouldn’t use the adjective “minimal” to describe any Qt app, no matter how short its main().
If you are actually looking for a minimal terminal, whose source code is intelligible and readily customizable, look no further than https://st.suckless.org/
The use of QTermWidget makes this almost entirely an exercise in building a hello-world Qt app and very little about building a terminal. That is all very well if you are looking to learn Qt—which is by no means an unworthy aim—but I wouldn’t use the adjective “minimal” to describe any Qt app, no matter how short its main().
If you are actually looking for a minimal terminal, whose source code is intelligible and readily customizable, look no further than https://st.suckless.org/