talkatu/talkatu

Update the demo to default the author to Alice and add a keybinding for ctrl-w

Testing Done:
Ran the demo and verified the author was set and that ctrl-w closed the window and therefore the application.

Reviewed at https://reviews.imfreedom.org/r/1281/
if get_option('vapi')
if not get_option('introspection')
error('Vala generation requires GObject Introspection.')
endif
add_languages('vala', native : false)
talkatu_vapi = gnome.generate_vapi('talkatu',
sources : talkatu_gir[0],
packages : [ 'gtk4' ],
install : true,
gir_dirs : meson.current_build_dir() / '..' / 'talkatu',
)
endif # vala