Summary:
the wiki page says the readme is duplicated into the wiki.

so, what we end up with is either

- they end up out of sync
- someone gets real angry because the wiki needs format markup while the
  readme must not have markup
- someone doesn't get angry and simply copies either markup or nomarkup to
  the respectively unsuitable target

it's an unsustainable situation... so instead let's point the readme to
the wiki and consider that the place where the documentation is maintained

Subscribers: kde-frameworks-devel

Tags: #frameworks

Differential Revision: https://phabricator.kde.org/D19779