Issue with the ReadME

[kliegeois]

The ReadMe suggests that the Xcode Command Line tools is sufficient to build the executable.

I tried it on a M1 Mac where they are installed but where the Xcode application is not installed.
While executing the swift command, I faced this error:

xcrun: error: unable to find utility "xctest", not a developer tool or in PATH

Searching on the web, it seems that it is required to install the Xcode application to have access to xctest.

It might be interesting to update the ReadMe to remove the "at least Xcode Command Line tools" as it might not be sufficient.