wezterm: By default connect mux to domain called unix

If we start wezterm muxing we now always connect to the same default
domain. This is a tiny step toward true multiplexing with wezterm.

terminal/.config/wezterm/wezterm.lua

@@ -24,6 +24,9 @@ if file_exists(colorsfile) == true then
 end
 
 local settings = {
+	unix_domains = {
+		{ name = "unix" },
+	},
 	enable_wayland = true, -- sadface :-(
 	xcursor_theme = "Adwaita",
 	enable_tab_bar = true,