wezterm: Allow toggling tab bar display

Tab display can be toggled on or off with `Ctrl+Shift+T`. The toggling
takes place per-window and not globally, so we can have a wezterm
terminal on desktop 1 with a tabbar and on desktop 2 without. Opening
a new terminal always defaults to an enabled tab bar.

terminal/.config/wezterm/maps.lua

@@ -100,6 +100,7 @@ local keys = {
 		action = act.EmitEvent("ActivatePaneDirection-Right"),
 	},
 	{ key = "a", mods = "CTRL|ALT", action = act.EmitEvent("toggle-leader") },
+	{ key = "T", mods = "CTRL", action = act.EmitEvent("toggle-tabbar") },
 }
 -- Leader + number to activate that tab
 for i = 1, 8 do