Add an about dialog and meson fixes

src/dialogs/about.rs

@@ -0,0 +1,46 @@
+use crate::config;
+use gtk::prelude::GtkWindowExt;
+use relm4::{gtk, ComponentParts, ComponentSender, SimpleComponent};
+
+pub struct AboutDialog {}
+
+pub struct Widgets {
+    main_window: gtk::Window,
+}
+
+impl SimpleComponent for AboutDialog {
+    type Input = ();
+    type Output = ();
+    type Init = gtk::Window;
+    type Root = ();
+    type Widgets = Widgets;
+
+    fn init_root() -> Self::Root {}
+
+    fn init(
+        main_window: Self::Init,
+        _root: &Self::Root,
+        _sender: ComponentSender<Self>,
+    ) -> ComponentParts<Self> {
+        let model = Self {};
+
+        let widgets = Widgets { main_window };
+
+        ComponentParts { model, widgets }
+    }
+
+    fn update_view(&self, widgets: &mut Self::Widgets, _sender: ComponentSender<Self>) {
+        let dialog = gtk::AboutDialog::builder()
+            .icon_name(config::APP_ID)
+            .name(config::NAME)
+            .authors(["Bnyro"])
+            .copyright("© 2023 Lemoa contributors")
+            .license_type(gtk::License::Gpl30)
+            .version(config::VERSION)
+            .modal(true)
+            .transient_for(&widgets.main_window)
+            .artists(["Bnyro <bnyro@tutanota.com>"])
+            .build();
+        dialog.present();
+    }
+}

src/dialogs/mod.rs

@@ -1 +1,2 @@
+pub mod about;
 pub mod editor;