Since the release of the qml executable several years ago, the intention was that the first line of a QML file can be something like

#!/bin/env qml

and the file can be marked executable, just as with any other Unix-style script. It works cross-platform (on desktop systems at least). But it's inconvenient to edit such a file in Creator, because it doesn't recognize the syntax of the whole file if the first line is of that form. I always have to comment out the first line with control-/ to edit, and then revert the change afterwards.

An example is https://github.com/ec1oud/icongen.qml