Documentation revamp update

[Nicolas Fella]

Hi,

I'm happy to announce a major milestone in our effort to improve our API
documentation website by porting it to QDoc.

We now have a preview of the new site available at
https://api-staging.kde.org/, with all Frameworks converted to the new
syntax.

Please have a look and report any issues. We do have some flexibility
regarding content and appearance, but please understand that we have to
work within what QDoc provides, so we might not be able to accommodate
all requests easily.

One major thing that's currently missing is a search function. There's
some thoughts and a WIP at
https://invent.kde.org/teams/documentation/sprints/-/issues/81. Help
with this and other web-development topics is welcome.

Currently the documentation syntax changes for the frameworks are in a
separate branch, we will merge these to master as we are going live with
the new site.

The current plan is to go live with Frameworks only once the site is
ready, other libraries can be converted/added over time.

You can find some instructions about converting in
https://invent.kde.org/-/snippets/3206

Thanks to everyone who contributed to this effort!

Cheers

Nico