documentation viewer backend(s)

[René J.V. Bertin]

Hi,

Someone coined the idea of implementing some sort of plugin-based backend mechanism for the documentation viewer. It seems something like that is already coming to QtWebView, though not immediately and almost certainly not with any intention of backporting it

https://codereview.qt-project.org/#/c/207651/

This would almost certainly ease the task and make the documentation plugin(s) depend directly only on QtWebView - insofar as  that component is itself an appropriate choice for an embedded documentation viewer.

R.