Add Lua Gnome template

[UrtsiSantsi]

Add a template that helps to get started with Gtk, Adwaita, Lua, Meson, Localization, Flatpak and ability to run in Gnome Builder. This will be a huge help for newcomers.
See https://gitlab.gnome.org/World/Rust/gtk-rust-template/, https://github.com/flattool/typescript-app-template, https://gitlab.gnome.org/monster/pygobject-template

[vtrlx]

This is a great idea. I already have this tutorial on my blog from which you can get started, but having a ready template is definitely something I neglected to do.

I will note however that I am not in a position to be able to fulfill everything you've requested—I do not know how Meson works (and have given up trying) and I have little interest in getting a template to be Builder-ready. I forked this project specifically to get away from existing tooling, which I personally found to be unworkable.

Happy to accept help on this one.