[Interest] Qt5 docs missing from Ubuntu 19.04

[Phil]

Thank you for reading this.

I'm not sure if this is a Qt or a Ubuntu issue or even a 
misunderstanding on my part.

/usr/share/doc/qt4-doc-html contains the qt4 help files whereas 
/usr/share/doc/qt5-doc-html does not contain a html directory and so 
there are no help files.

I'm wondering what other Ubuntu uses have done to overcome this problem?

-- 
Regards,
Phil