docs: Metal support

[datwelk]

The documentation under QML setup says:

Warning
Only OpenGL backend is supported for now!

(https://maplibre.org/maplibre-native-qt/docs/md_docs_2Usage.html)

Is this only true for QML apps, and not for widgets? Does the Metal backend work for Widgets?

[ntadej]

It seems you have found a bug in the documentation. Metal is supported both for Widgets and QML. Will fix ASAP.