Visual revamp
This commit introduces a sidebar that allows you to navigate between the various gallery pages, this sidebar also contains a home button to come back to the initial page and a search field to search for the desired page.
Also all gallery pages now use the same named imports that other KDE applications use (e.g QQC2.Label and Kirigami.Heading instead of Controls.Label and Heading).
Now you can spend less time fighting the UI and more time seeing the gallery. :)
Edited by Felipe Kinoshita