QByteArray Constructor: add Uninitialized example

You can read how constructs a byte array of size size with uninitialized contents here.

I suggest add
Example:

QByteArray a(123, Qt::Initialization::Uninitialized);

Because not clear that I shouldn't use QByteArray a(123, Qt::Initialization) but QByteArray a(123, Qt::Initialization::Uninitialized).