[Development] Maintainers, your action needed; Qt 5.15.0 Changes Files

[Jani Heikkinen]

Hi,
Initial ones here: https://codereview.qt-project.org/q/message:%2522Add+changes+file+for+Qt+5.15.0%2522

Please finalize asap,we should get these in before RC (which is coming at the end of April)

br,
jani