Add a HUD event to allow new players to understand

mods/ctf/ctf_modes/ctf_mode_classes/classes.lua

@@ -144,6 +144,12 @@ ctf_melee.simple_register_sword("ctf_mode_classes:knight_sword", {
 			if not ctl.sneak and not ctl.aux1 then return end
 		end
 		if not ctf_modebase.match_started then
+			local uname = user:get_player_name()
+			hud_events.new(uname, {
+				quick = true,
+				text = "You cannot activate special ability during build time!",
+				color = "warning",
+			})
 			return
 		end
 		local pname = user:get_player_name()
@@ -219,6 +225,12 @@ ctf_ranged.simple_register_gun("ctf_mode_classes:ranged_rifle", {
 			return
 		end
 		if not ctf_modebase.match_started then
+			local uname = user:get_player_name()
+			hud_events.new(uname, {
+				quick = true,
+				text = "You cannot activate special ability during build time!",
+				color = "warning",
+			})
 			return
 		end
 		if itemstack:get_wear() == 0 then
@@ -302,6 +314,12 @@ ctf_healing.register_bandage("ctf_mode_classes:support_bandage", {
 		    if not ctl.sneak and not ctl.aux1 then return end
         end
 		if not ctf_modebase.match_started then
+			local uname = user:get_player_name()
+			hud_events.new(uname, {
+				quick = true,
+				text = "You cannot activate special ability during build time!",
+				color = "warning",
+			})
 			return
 		end
 		local pname = user:get_player_name()