[Development] Assistant WebKit/WebEngine support

[Jaroslaw Kobus]

I think the option 2 (enhancements in QTextBrowser) is the best one, since the time investment spent on it will benefit for all users of QTextBrowser, not only those using Qt help system. So big +1 here!

However, if we go with the webengine (or webkit) way, I would be very happy that the existing solution (crappy QTextBrowser) is still there as a fallback, even if the content may start to look even more ugly (due to potential "style" redesign of qch files, which most probably will happen when we have full functional web browser in). I remember the old days, when we had mandatory webkit: I never compiled it, since it was a big pain (many external dependencies, many times it just didn't compile, very long time spent on compilation). Usually the result was that after half a day spent on preparation / compilation, I saw not working help. So I had to use online docs in my browser.

Another option which comes to my mind is:

Option 8: Make the webengine project configurable / customizable enough, so that we may cut off all networking and stuff we don't need, keeping only the pure HTML rendering. This would be also benefit for others - maybe then much more people would start using it. I realize that this would probably be a huge refactoring and a long term solution. However, maybe it's worth to think about it now, before Qt6...

Jarek